WO2010098074A1 - Heat pump system - Google Patents

Abstract

A heat pump system (1) is equipped with a heat source side refrigerant circuit (20) including a heat source side compressor (21), a first utilization side heat exchanger (41a) which functions as a radiator for a heat source side refrigerant, and a heat source side heat exchanger (24) which functions as a radiator for the heat source side refrigerant; and a utilization side refrigerant circuit (40a) including a utilization side compressor (62a) which compresses utilization side refrigerant having a gauge pressure of 2.8 MPa or less corresponding to the saturation gas temperature of 65°C, a refrigerant-water heat exchanger (65a) which functions as a radiator for utilization side refrigerant and heats a water medium, and the first utilization side heat exchanger (41a) which functions as an evaporator for the utilization side refrigerant by radiating heat of the heat source side refrigerant. The weight of the utilization side refrigerant enclosed in the utilization side refrigerant circuit (40a) is 1-3 times of the weight of refrigerating machine oil which is enclosed for the purpose of lubricating the utilization side compressor (62a).

Description

Heat pump system

The present invention relates to a heat pump system, and more particularly to a heat pump system capable of heating an aqueous medium using a heat pump cycle.

Conventionally, there is a heat pump water heater capable of heating water using a heat pump cycle as disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 60-164157). Such a heat pump water heater mainly includes a compressor, a refrigerant-water heat exchanger, and a heat source side heat exchanger, and heats the water by the heat radiation of the refrigerant in the refrigerant-water heat exchanger. It is comprised so that the warm water produced may be supplied to a hot water tank.

In the above conventional heat pump water heater, in order to supply hot hot water to the hot water tank, not only a refrigerant-water heat exchanger but also an auxiliary heater is used to heat the water or increase the discharge pressure of the compressor. Therefore, it is necessary to perform the operation under such a condition that the operation efficiency is poor, which is not preferable.
An object of the present invention is to enable a high-temperature aqueous medium to be obtained in a heat pump system capable of heating an aqueous medium using a heat pump cycle.

The heat pump system according to the first aspect includes a heat source side refrigerant circuit and a use side refrigerant circuit. The heat source side refrigerant circuit functions as a heat source side compressor that compresses the heat source side refrigerant, a first usage-side heat exchanger that can function as a radiator of the heat source side refrigerant, and an evaporator of the heat source side refrigerant. A heat source side heat exchanger capable of The use side refrigerant circuit functions as a use side compressor that compresses the use side refrigerant whose pressure corresponding to a saturated gas temperature of 65 ° C. is 2.8 MPa or less in gauge pressure, and functions as a radiator of the use side refrigerant to supply an aqueous medium. It has a refrigerant-water heat exchanger that can be heated, and a first user-side heat exchanger that can function as an evaporator of the user-side refrigerant by radiating heat from the heat-source-side refrigerant. The use side compressor, the first use side heat exchanger, and the refrigerant-water heat exchanger constitute a first use unit, and function as an evaporator of the use side refrigerant. The length of the refrigerant pipe from the use side compressor to the use side compressor is 3 m or less, and in the use side refrigerant circuit, the refrigerating machine oil contained in the use side refrigerant discharged from the use side compressor is separated and the use side compression is performed. The oil separation mechanism for returning to the intake of the machine is not provided, and the weight of the utilization side refrigerant enclosed in the utilization side refrigerant circuit is 1 of the weight of the refrigerating machine oil enclosed for lubrication of the utilization side compressor. Double to triple.

In this heat pump system, in the first usage-side heat exchanger, the usage-side refrigerant circulating in the usage-side refrigerant circuit is heated by the heat radiation of the heat-source-side refrigerant circulating in the heat source-side refrigerant circuit. Since the circuit can obtain a refrigeration cycle having a temperature higher than that of the refrigeration cycle in the heat source side refrigerant circuit by using the heat obtained from the heat source side refrigerant, a high temperature can be obtained by radiating heat from the utilization side refrigerant in the refrigerant-water heat exchanger. An aqueous medium can be obtained.
At this time, like this heat pump system, the use side refrigerant circuit is included in the first use unit, and further, from the first use side heat exchanger functioning as an evaporator of the use side refrigerant to the use side compressor. From the viewpoint of the circuit configuration that the length of the refrigerant pipe is a short refrigerant pipe of 3 m or less, since there is a low possibility that the refrigeration oil is accumulated in a part other than the use side compressor in the use side refrigerant circuit, If it exists, it is thought that the quantity of the refrigerating machine oil enclosed with a utilization side refrigerant | coolant in a utilization side refrigerant circuit can be decreased.

On the other hand, from the viewpoint of the purpose of obtaining a high-temperature aqueous medium, as in this heat pump system, as a refrigerant on the use side, the pressure corresponding to the saturation gas temperature of 65 ° C. is as high as a refrigerant having a gauge pressure of 2.8 MPa or less. It is preferable to use a refrigerant having a boiling point (that is, a refrigerant having a low-pressure saturation characteristic). However, if a refrigerant having such a low-pressure saturation characteristic is used for the purpose of obtaining a high-temperature aqueous medium, it is used under a high-temperature condition. As a result, the usage-side refrigerant in the gas state that dissolves in the refrigeration oil increases, and as a result, the viscosity of the refrigeration oil decreases, and the amount of refrigeration oil discharged from the usage-side compressor together with the refrigerant increases. Since in-machine lubrication may be insufficient, it is considered necessary to increase the amount of refrigerating machine oil enclosed in the use side refrigerant circuit together with the use side refrigerant.
Further, when the temperature of the refrigeration oil in the use side compressor is lower than the condensation temperature of the use side refrigerant, the use side refrigerant may condense in the use side compressor, and dilution of the refrigeration oil may occur. In particular, in a system that obtains a high-temperature aqueous medium such as this heat pump system, since the condensation temperature of the use-side refrigerant is high, the dilution of the refrigerating machine oil is very easy to proceed, and as a result, the viscosity coefficient of the refrigerating machine oil decreases. Since the amount of refrigerating machine oil discharged from the use side compressor together with the refrigerant increases, there is a risk of insufficient lubrication in the use side compressor. From this point as well, the use side refrigerant circuit is sealed together with the use side refrigerant. It is considered necessary to increase the amount of refrigerating machine oil.

As described above, when the amount of the refrigerating machine oil is increased, the oil separating mechanism for separating the refrigerating machine oil discharged accompanying the use side refrigerant discharged from the use side compressor and returning it to the suction of the use side compressor. Is preferably provided.
However, in use under high-temperature conditions such as this heat pump system, as described above, the use-side refrigerant in the gas state that dissolves in the refrigerating machine oil increases, and the dilution of the refrigerating machine oil is likely to proceed. Since the amount of refrigeration oil discharged along with the use-side refrigerant discharged from the side compressor increases, the amount of use-side refrigerant returned to the intake of the use-side compressor together with the refrigeration oil when the oil separation mechanism is provided May increase the driving efficiency.
Therefore, in this heat pump system, the purpose of obtaining a high-temperature aqueous medium (condensation temperature is high, increasing the amount of dissolved use-side refrigerant in the refrigerating machine oil and promoting the dilution of refrigerating machine oil by condensing the use-side refrigerant) and The possibility that the refrigeration oil is collected in a portion of the usage side refrigerant circuit other than the usage side compressor is low (that is, the usage side refrigerant circuit is included in the first usage unit and the evaporator of the usage side refrigerant is used. Considering the viewpoint of the circuit configuration that the refrigerant pipe from the first usage-side heat exchanger functioning as the refrigerant pipe to the usage-side compressor is a short refrigerant pipe having a length of 3 m or less), Unlike the concept of the quantity, an oil separation mechanism for separating the refrigerating machine oil contained in the usage-side refrigerant discharged from the usage-side compressor and returning it to the suction of the usage-side compressor must be provided in the usage-side refrigerant circuit. , So that to one to three times the weight of the refrigerating machine oil enclosed for lubrication of the use-side refrigerant circuit usage-side compressor the weight of the usage-side refrigerant to be sealed in.
As a result, this heat pump system allows an increase in the amount of the use-side refrigerant returned to the intake of the use-side compressor together with the refrigeration oil, while suppressing a decrease in operating efficiency and insufficient lubrication in the use-side compressor. Meanwhile, a high-temperature aqueous medium can be obtained.

In the heat pump system according to the second aspect, in the heat pump system according to the first aspect, the use-side refrigerant has a pressure corresponding to a saturated gas temperature of 65 ° C. of 2.0 MPa (gauge pressure) or less.
In this heat pump system, a refrigerant having a lower pressure saturation characteristic, such as a refrigerant having a pressure corresponding to a saturation gas temperature of 65 ° C. and a gauge pressure of 2.0 MPa or less, is used as a use side refrigerant. The aqueous medium can be obtained, and the effect of the heat pump system according to the first aspect becomes remarkable.

A heat pump system according to a third aspect is the heat pump system according to the first or second aspect, wherein the usage side refrigerant circuit is an accumulator capable of temporarily storing the usage side refrigerant for suction of the usage side compressor. And a refrigerant-water heat exchange side flow rate control valve capable of changing the flow rate of the use side refrigerant flowing through the refrigerant-water heat exchanger, and the use side compressor lacks refrigerating machine oil. If it is determined, the oil recovery operation is performed in which the use-side refrigerant including the refrigeration oil in the refrigerant-water heat exchanger is returned to the accumulator through the refrigerant-water heat exchange side flow control valve and the first use-side heat exchanger. .
In the heat pump system according to the first or second aspect, since the oil separation mechanism is not provided, the refrigeration oil is introduced into the refrigerant-water heat exchanger that functions as a radiator for the utilization side refrigerant together with the utilization side refrigerant. In addition, under high temperature conditions, a refrigerant that functions as a radiator for the usage-side refrigerant is likely to cause two-phase separation between the usage-side refrigerant in the liquid state and the refrigeration oil in the water-heat exchanger. Refrigerating machine oil tends to accumulate in the water heat exchanger.

Therefore, in this heat pump system, the usage-side refrigerant circuit can temporarily store the usage-side refrigerant for the suction of the usage-side compressor, and the flow rate of the usage-side refrigerant flowing through the refrigerant-water heat exchanger. Is further provided with a refrigerant-water heat exchanger flow rate control valve, and if it is determined that the use side compressor is deficient in refrigerating machine oil, the refrigerant-water heat exchanger Utilization of usage-side refrigerant containing refrigeration oil under low-temperature conditions where two-phase separation between the usage-side refrigerant in the liquid state and the refrigeration oil is unlikely to occur through the refrigerant-water heat exchange side flow control valve and the first usage-side heat exchanger. By performing the oil recovery operation to return to the side accumulator, it is possible to prevent the shortage of refrigeration oil in the use side compressor. Further, during the oil recovery operation, the operation of heating the water refrigerant can be continued by causing the refrigerant-water heat exchanger to function as a radiator for the use-side refrigerant.

In the heat pump system according to the fourth aspect, in the heat pump system according to the third aspect, the determination as to whether or not the refrigeration oil is insufficient in the use side compressor is based on the temperature of the use side refrigerant at the discharge of the use side compressor or This is based on the temperature of the aqueous medium at the outlet of the refrigerant-water heat exchanger.

In this heat pump system, whether or not the use side compressor is deficient in refrigeration oil is determined based on the temperature of the use side refrigerant at the discharge of the use side compressor or the temperature of the aqueous medium at the outlet of the refrigerant-water heat exchanger. Therefore, taking into account the degree of melting of the use side refrigerant in the refrigeration oil in the use side compressor and the degree of two-phase separation between the use side refrigerant and the refrigeration oil in the refrigerant-water heat exchanger. It is possible to appropriately determine whether or not the use side compressor has insufficient refrigeration oil.

It is a schematic block diagram of the heat pump system concerning 1st Embodiment and the modification 1 of this invention. It is a flowchart which shows the oil recovery driving | operation control of the utilization side refrigerant circuit in the modification 1 of 1st Embodiment, the modification 1 of 2nd Embodiment, and the modification 1 of 3rd Embodiment. It is a schematic block diagram of the heat pump system concerning the modification 2 of 1st Embodiment. It is a flowchart which shows the defrost operation in the modification 2 of 1st Embodiment, the modification 2 of 2nd Embodiment, and the modification 2 of 3rd Embodiment. It is a schematic block diagram of the heat pump system concerning the modification 3 of 1st Embodiment. It is a schematic block diagram of the heat pump system concerning 2nd Embodiment and the modification 1 of this invention. It is a schematic block diagram of the heat pump system concerning the modification 2 of 2nd Embodiment. It is a schematic block diagram of the heat pump system concerning the modification 3 of 2nd Embodiment. It is a schematic block diagram of the heat pump system concerning the modification 3 of 2nd Embodiment. It is a schematic block diagram of the heat pump system concerning the modification 3 of 2nd Embodiment. It is a schematic block diagram of the heat pump system concerning the modification 4 of 2nd Embodiment. It is a schematic block diagram of the heat pump system concerning 3rd Embodiment and the modification 1 of this invention. It is a schematic block diagram of the heat pump system concerning the modification 2 of 3rd Embodiment. It is a schematic block diagram of the heat pump system concerning the modification 3 of 3rd Embodiment. It is a schematic block diagram of the heat pump system concerning the modification 4 of 2nd Embodiment. It is a schematic block diagram of the heat pump system concerning the modification 4 of 2nd Embodiment. It is a schematic block diagram of the heat pump system concerning the modification 4 of 2nd Embodiment. It is a schematic block diagram of the heat pump system concerning the modification 5 of 2nd Embodiment.

Hereinafter, an embodiment of a heat pump system according to the present invention will be described with reference to the drawings.
(First embodiment)
<Configuration>
-The entire-
FIG. 1 is a schematic configuration diagram of a heat pump system 1 according to the first embodiment of the present invention. The heat pump system 1 is an apparatus capable of performing an operation for heating an aqueous medium using a vapor compression heat pump cycle.
The heat pump system 1 mainly includes a heat source unit 2, a first usage unit 4a, a liquid refrigerant communication tube 13, a gas refrigerant communication tube 14, a hot water storage unit 8a, a hot water heating unit 9a, and an aqueous medium communication tube 15a. The water source communication pipe 16a is provided, and the heat source unit 2 and the first usage unit 4a are connected via the refrigerant communication pipes 13 and 14, thereby constituting the heat source side refrigerant circuit 20 and the first usage. The unit 4a constitutes the use side refrigerant circuit 40a, and the first use unit 4a, the hot water storage unit 8a, and the hot water heating unit 9a are connected via the aqueous medium communication pipes 15a and 16a, thereby constituting the aqueous medium circuit 80a. is doing. In the heat source side refrigerant circuit 20, HFC-410A, which is a kind of HFC refrigerant, is sealed as a heat source refrigerant, and an ester or ether refrigerating machine oil compatible with the HFC refrigerant is used as the heat source. It is enclosed for lubrication of the side compressor 21 (described later). Further, HFC-134a, which is a kind of HFC refrigerant, is sealed in the use side refrigerant circuit 40a as a use side refrigerant, and ester or ether type refrigerating machine oil having compatibility with the HFC refrigerant. Is enclosed for lubrication of the use side compressor 62a. In addition, as a use side refrigerant | coolant, from a viewpoint that the refrigerant | coolant advantageous to a high temperature refrigerating cycle is used, the pressure corresponding to saturation gas temperature 65 degreeC is 2.8 Mpa or less at the maximum at a gauge pressure, Preferably, it is 2.0 Mpa. The following refrigerants are preferably used. Moreover, the weight of the utilization side refrigerant | coolant enclosed with the utilization side refrigerant circuit 40a is 1 to 3 times the weight of the refrigerating machine oil enclosed for lubrication of the utilization side compressor 62a. HFC-134a is a kind of refrigerant having such saturation pressure characteristics. Further, water as an aqueous medium circulates in the aqueous medium circuit 80a.

-Heat source unit-
The heat source unit 2 is installed outdoors and is connected to the utilization unit 4a via the refrigerant communication tubes 13 and 14, and constitutes a part of the heat source side refrigerant circuit 20.
The heat source unit 2 mainly includes a heat source side compressor 21, an oil separation mechanism 22, a heat source side switching mechanism 23, a heat source side heat exchanger 24, a heat source side expansion mechanism 25, a suction return pipe 26, and a supercooling. A heat source side accumulator 28, a liquid side closing valve 29, and a gas side closing valve 30.
The heat source side compressor 21 is a mechanism that compresses the heat source side refrigerant. Here, a rotary type or scroll type volumetric compression element (not shown) housed in a casing (not shown), Similarly, a hermetic compressor driven by a heat source side compressor motor 21a accommodated in the casing is employed. A high-pressure space (not shown) filled with the heat-source-side refrigerant after being compressed by the compression element is formed in the casing of the heat-source-side compressor 21, and refrigerating machine oil is stored in the high-pressure space. ing. The heat source side compressor motor 21a can change the rotation speed (that is, the operating frequency) by an inverter device (not shown), thereby enabling capacity control of the heat source side compressor 21.

The oil separation mechanism 22 is a mechanism for separating the refrigeration oil contained in the heat source side refrigerant discharged from the heat source side compressor 21 and returning it to the suction of the heat source side compressor. An oil separator 22a provided in the heat source side discharge pipe 21b, and an oil return pipe 22b connecting the oil separator 22a and the heat source side suction pipe 21c of the heat source side compressor 21 are provided. The oil separator 22 a is a device that separates the refrigeration oil contained in the heat source side refrigerant discharged from the heat source side compressor 21. The oil return pipe 22 b has a capillary tube, and is a refrigerant pipe that returns the refrigeration oil separated from the heat source side refrigerant in the oil separator 22 a to the heat source side suction pipe 21 c of the heat source side compressor 21.
The heat source side switching mechanism 23 is a heat source side heat radiation operation state in which the heat source side heat exchanger 24 functions as a heat source side refrigerant radiator and a heat source side evaporation operation state in which the heat source side heat exchanger 24 functions as an evaporator of the heat source side refrigerant. A heat source side discharge pipe 21b, a heat source side suction pipe 21c, a first heat source side gas refrigerant pipe 23a connected to the gas side of the heat source side heat exchanger 24, and a gas It is connected to the second heat source side gas refrigerant pipe 23 b connected to the side closing valve 30. The heat source side switching mechanism 23 communicates the heat source side discharge pipe 21b and the first heat source side gas refrigerant pipe 23a, and communicates the second heat source side gas refrigerant pipe 23b and the heat source side suction pipe 21c (heat source side heat dissipation). 1) (refer to the solid line of the heat source side switching mechanism 23 in FIG. 1), the heat source side discharge pipe 21b and the second heat source side gas refrigerant pipe 23b are communicated, and the first heat source side gas refrigerant pipe 23a Switching to communicate with the heat source side suction pipe 21c (corresponding to the heat source side evaporation operation state, see the broken line of the heat source side switching mechanism 23 in FIG. 1) can be performed. The heat source side switching mechanism 23 is not limited to the four-way switching valve, and has a function of switching the flow direction of the heat source side refrigerant as described above, for example, by combining a plurality of electromagnetic valves. It may be configured.

The heat source side heat exchanger 24 is a heat exchanger that functions as a heat source side refrigerant radiator or an evaporator by exchanging heat between the heat source side refrigerant and outdoor air, and a heat source side liquid refrigerant tube 24a on the liquid side thereof. Are connected, and the first heat source side gas refrigerant pipe 23a is connected to the gas side thereof. The outdoor air that exchanges heat with the heat source side refrigerant in the heat source side heat exchanger 24 is supplied by the heat source side fan 32 driven by the heat source side fan motor 32a.
The heat source side expansion valve 25 is an electric expansion valve that depressurizes the heat source side refrigerant flowing through the heat source side heat exchanger 24, and is provided in the heat source side liquid refrigerant pipe 24a.
The suction return pipe 26 is a refrigerant pipe that branches a part of the heat source side refrigerant flowing through the heat source side liquid refrigerant pipe 24a and returns it to the suction of the heat source side compressor 21, and here, one end thereof is the heat source side liquid refrigerant pipe 24a. The other end is connected to the heat source side suction pipe 21c. The suction return pipe 26 is provided with a suction return expansion valve 26a capable of opening degree control. The suction return expansion valve 26a is an electric expansion valve.

The subcooler 27 heats the heat source side refrigerant flowing through the heat source side liquid refrigerant pipe 24a and the heat source side refrigerant flowing through the suction return pipe 26 (more specifically, the refrigerant after being decompressed by the suction return expansion valve 26a). It is a heat exchanger that performs exchange.
The heat source side accumulator 28 is provided in the heat source side suction pipe 21c, and temporarily accumulates the heat source side refrigerant circulating in the heat source side refrigerant circuit 20 before being sucked into the heat source side compressor 21 from the heat source side suction pipe 21c. It is a container for.
The liquid side closing valve 29 is a valve provided at a connection portion between the heat source side liquid refrigerant pipe 24 a and the liquid refrigerant communication pipe 13. The gas side shut-off valve 30 is a valve provided at a connection portion between the second heat source side gas refrigerant pipe 23 b and the gas refrigerant communication pipe 14.
The heat source unit 2 is provided with various sensors. Specifically, the heat source unit 2 includes a heat source side suction pressure sensor 33 that detects a heat source side suction pressure Ps 1 that is a pressure of the heat source side refrigerant in the suction of the heat source side compressor 21, and a discharge in the heat source side compressor 21. The heat source side discharge pressure sensor 34 that detects the heat source side discharge pressure Pd1 that is the pressure of the heat source side refrigerant, and the heat source side heat exchanger temperature Thx that is the temperature of the heat source side refrigerant on the liquid side of the heat source side heat exchanger 24 are detected. A heat source side heat exchange temperature sensor 35 and an outside air temperature sensor 36 for detecting the outside air temperature To are provided.

-Liquid refrigerant communication tube-
The liquid refrigerant communication tube 13 is connected to the heat source side liquid refrigerant tube 24a via the liquid side shut-off valve 29, and the heat source side switching mechanism 23 functions as a heat source side refrigerant radiator in the heat source side heat radiation operation state. The heat source side refrigerant can be led out of the heat source unit 2 from the outlet of the heat exchanger 24, and the heat source side switching mechanism 23 functions as an evaporator of the heat source side refrigerant from the outside of the heat source unit 2 in the heat source side evaporation operation state. This is a refrigerant tube capable of introducing the heat source side refrigerant into the inlet of the heat source side heat exchanger 24.
-Gas refrigerant communication tube-
The gas refrigerant communication pipe 14 is connected to the second heat source side gas refrigerant pipe 23b via the gas side shutoff valve 30, and the heat source side switching mechanism 23 from outside the heat source unit 2 in the heat source side heat radiation operation state. It is possible to introduce the heat source side refrigerant into the suction of the heat source 21, and the heat source side switching mechanism 23 may lead the heat source side refrigerant out of the heat source unit 2 from the discharge of the heat source side compressor 21 in the heat source side evaporation operation state. Possible refrigerant pipe.

-First use unit-
The first usage unit 4 a is installed indoors and connected to the heat source unit 2 via the refrigerant communication tubes 13 and 14 and constitutes a part of the heat source side refrigerant circuit 20. Moreover, the 1st utilization unit 4a comprises the utilization side refrigerant circuit 40a. Furthermore, the 1st utilization unit 4a is connected to the hot water storage unit 8a and the hot water heating unit 9a via the aqueous medium communication pipes 15a and 16a, and constitutes a part of the aqueous medium circuit 80a.
The first usage unit 4a mainly includes a first usage-side heat exchanger 41a, a first usage-side flow rate adjustment valve 42a, a usage-side compressor 62a, a refrigerant-water heat exchanger 65a, and a refrigerant-hydrothermal exchange. It has a side flow rate adjustment valve 66a, a use side accumulator 67a, and a circulation pump 43a.
The first usage-side heat exchanger 41a is a heat exchanger that functions as a radiator for the heat-source-side refrigerant by performing heat exchange between the heat-source-side refrigerant and the usage-side refrigerant, and is a liquid in a flow path through which the heat-source-side refrigerant flows. A first use side liquid refrigerant tube 45a is connected to the side, and a first use side gas refrigerant tube 54a is connected to the gas side of the flow path through which the heat source side refrigerant flows, and the use side refrigerant. A cascade side liquid refrigerant pipe 68a is connected to the liquid side of the flow path through which the refrigerant flows, and a second cascade side gas refrigerant pipe 69a is connected to the gas side of the flow path through which the use side refrigerant flows. The liquid refrigerant communication pipe 13 is connected to the first usage side liquid refrigerant pipe 45a, the gas refrigerant communication pipe 14 is connected to the first usage side gas refrigerant pipe 54a, and the cascade side liquid refrigerant pipe 68a. The refrigerant-water heat exchanger 65a is connected to the second cascade side gas refrigerant pipe 69a, and the use side compressor 62a is connected to the second cascade side gas refrigerant pipe 69a.

The first usage-side flow rate adjustment valve 42a is an electric expansion valve capable of changing the flow rate of the heat source-side refrigerant flowing through the first usage-side heat exchanger 41a by performing opening degree control. It is provided in the refrigerant pipe 45a.
The use side compressor 62a is a mechanism for compressing the use side refrigerant. Here, a rotary type or scroll type volumetric compression element (not shown) housed in a casing (not shown) is used. Similarly, a hermetic compressor driven by a use side compressor motor 63a accommodated in the casing is employed. A high-pressure space (not shown) filled with the heat-source-side refrigerant after being compressed by the compression element is formed in the casing of the use-side compressor 62a, and refrigeration oil is stored in the high-pressure space. ing. The use-side compressor motor 63a can vary the rotation speed (that is, the operating frequency) by an inverter device (not shown), thereby enabling capacity control of the use-side compressor 62a. Further, a cascade side discharge pipe 70a is connected to the discharge of the use side compressor 62a, and a cascade side intake pipe 71a is connected to the intake of the use side compressor 62a. The cascade side suction pipe 71a is connected to the second cascade side gas refrigerant pipe 69a. Here, the length of the refrigerant pipe from the first usage-side heat exchanger 41a functioning as an evaporator for the usage-side refrigerant to the usage-side compressor 62a (more specifically, suction of the usage-side compressor 62a) (that is, the suction side) The total length of the second cascade side gas refrigerant pipe 69a and the cascade side suction pipe 71a) is very short, 3 m or less.

The refrigerant-water heat exchanger 65a is a heat exchanger that functions as a heat radiator for the usage-side refrigerant by exchanging heat between the usage-side refrigerant and the aqueous medium. The cascade side liquid refrigerant pipe 68a is connected to the gas side of the flow path through which the use side refrigerant flows, and the first cascade side gas refrigerant pipe 72a is connected to the flow path through which the aqueous medium flows. A first usage-side water inlet pipe 47a is connected to the inlet side, and a first usage-side water outlet pipe 48a is connected to the outlet side of the flow path through which the aqueous medium flows. The first cascade side gas refrigerant pipe 72a is connected to the cascade side discharge pipe 70a, the aqueous medium communication pipe 15a is connected to the first use side water inlet pipe 47a, and the first use side water outlet pipe is connected. The aqueous medium communication pipe 16a is connected to 48a.
The refrigerant-water heat exchange side flow rate adjustment valve 66a is an electric expansion valve capable of varying the flow rate of the use side refrigerant flowing through the refrigerant-water heat exchanger 65a by controlling the opening degree. It is provided in the pipe 68a.

The use side accumulator 67a is provided in the cascade side suction pipe 71a, and temporarily stores the use side refrigerant circulating in the use side refrigerant circuit 40a before being sucked from the cascade side suction pipe 71a into the use side compressor 62a. It is a container for.
As described above, the use side compressor 62a, the refrigerant-water heat exchanger 65a, the refrigerant-water heat exchange side flow rate adjustment valve 66a, and the first use side heat exchanger 41a connect the refrigerant pipes 71a, 70a, 72a, 68a, 69a. Thus, the use-side refrigerant circuit 40a is configured by being connected to each other. In addition, unlike the heat source side refrigerant circuit 20, the utilization side refrigerant circuit 40a separates the refrigeration oil contained in the utilization side refrigerant discharged from the utilization side compressor 62a and returns it to the intake of the utilization side compressor 62a. No oil separation mechanism is provided.
The circulation pump 43a is a mechanism for boosting the aqueous medium. Here, a pump in which a centrifugal or positive displacement pump element (not shown) is driven by a circulation pump motor 44a is employed. The circulation pump 43a is provided in the first usage-side water outlet pipe 48a. The circulation pump motor 44a can vary the rotation speed (that is, the operating frequency) by an inverter device (not shown), thereby enabling capacity control of the circulation pump 43a.

Accordingly, the first usage unit 4a causes the first usage-side heat exchanger 41a to radiate heat by causing the first usage-side heat exchanger 41a to function as a heat radiator for the heat-source-side refrigerant introduced from the gas refrigerant communication tube 14. The used heat source side refrigerant is led out to the liquid refrigerant communication pipe 13, and the use side refrigerant circulating in the use side refrigerant circuit 40a is heated by the heat radiation of the heat source side refrigerant in the first use side heat exchanger 41a, and this heated use side After the refrigerant is compressed in the use side compressor 62a, it is possible to perform a hot water supply operation for heating the aqueous medium by radiating heat in the refrigerant-water heat exchanger 65a.
The first usage unit 4a is provided with various sensors. Specifically, the first usage unit 4a includes a first usage-side heat exchange temperature sensor that detects the first usage-side refrigerant temperature Tsc1, which is the temperature of the heat-source-side refrigerant on the liquid side of the first usage-side heat exchanger 41a. 50a, a first refrigerant-water heat exchanger temperature sensor 73a for detecting a cascade-side refrigerant temperature Tsc2 which is a temperature of a use-side refrigerant on the liquid side of the refrigerant-water heat exchanger 65a, and an inlet of the refrigerant-water heat exchanger 65a An aqueous medium outlet temperature sensor 51a that detects an aqueous medium inlet temperature Twr that is the temperature of the aqueous medium in the water medium, and an aqueous medium outlet that detects an aqueous medium outlet temperature Twl that is the temperature of the aqueous medium at the outlet of the refrigerant-water heat exchanger 65a A temperature sensor 52a, a use side suction pressure sensor 74a that detects a use side suction pressure Ps2 that is a pressure of the use side refrigerant in the suction of the use side compressor 62a, and a discharge of the use side compressor 62a A use-side discharge pressure sensor 75a that detects a use-side discharge pressure Pd2 that is the pressure of the use-side refrigerant and a use-side discharge that detects a use-side discharge temperature Td2 that is the temperature of the use-side refrigerant in the discharge of the use-side compressor 62a. A temperature sensor 76a is provided.

-Hot water storage unit-
The hot water storage unit 8a is installed indoors, is connected to the first usage unit 4a via the aqueous medium communication pipes 15a and 16a, and constitutes a part of the aqueous medium circuit 80a.
The hot water storage unit 8a mainly includes a hot water storage tank 81a and a heat exchange coil 82a.
The hot water storage tank 81a is a container for storing water as an aqueous medium supplied for hot water supply, and a hot water supply pipe 83a is connected to the upper part of the hot water storage tank 81a for sending hot water to a faucet or a shower. A water supply pipe 84a for replenishing the aqueous medium consumed by the hot water supply pipe 83a is connected to the lower part.
The heat exchange coil 82a is provided in the hot water storage tank 81a, and heats the aqueous medium in the hot water storage tank 81a by exchanging heat between the aqueous medium circulating in the aqueous medium circuit 80a and the aqueous medium in the hot water storage tank 81a. A water medium communication pipe 16a is connected to an inlet of the heat exchanger, and an aqueous medium communication pipe 15a is connected to an outlet of the heat exchanger.

Thereby, the hot water storage unit 8a can heat the aqueous medium in the hot water storage tank 81a by the aqueous medium circulating in the aqueous medium circuit 80a heated in the first usage unit 4a and store it as hot water. Here, as the hot water storage unit 8a, a hot water storage unit of a type in which an aqueous medium heated by heat exchange with the aqueous medium heated in the first usage unit 4a is stored in a hot water storage tank is used. You may employ | adopt the type of hot water storage unit which accumulates the aqueous medium heated in the unit 4a in the hot water storage tank.
The hot water storage unit 8a is provided with various sensors. Specifically, the hot water storage unit 8a is provided with a hot water storage temperature sensor 85a for detecting the hot water storage temperature Twh which is the temperature of the aqueous medium stored in the hot water storage tank 81a.
-Hot water heating unit-
The hot water heating unit 9a is installed indoors, is connected to the first usage unit 4a via the aqueous medium communication pipes 15a and 16a, and constitutes a part of the aqueous medium circuit 80a.

The hot water heating unit 9a mainly has a heat exchange panel 91a, and constitutes a radiator, a floor heating panel, and the like.
In the case of a radiator, the heat exchange panel 91a is provided near the wall of the room, and in the case of a floor heating panel, the heat exchange panel 91a is provided under the floor of the room, and the water medium radiator circulating in the water medium circuit 80a. The aqueous medium communication pipe 16a is connected to the inlet of the heat exchanger, and the aqueous medium communication pipe 15a is connected to the outlet of the heat exchanger.
-Aqueous medium connection pipe-
The aqueous medium communication pipe 15a is connected to the outlet of the heat exchange coil 82a of the hot water storage unit 8a and the outlet of the heat exchange panel 91a of the hot water heating unit 9a. The aqueous medium communication pipe 16a is connected to the inlet of the heat exchange coil 82a of the hot water storage unit 8a and the inlet of the heat exchange panel 91a of the hot water heating unit 9a. The aqueous medium communication pipe 16a is switched to supply the aqueous medium circulating in the aqueous medium circuit 80a to both the hot water storage unit 8a and the hot water heating unit 9a, or to either the hot water storage unit 8a or the hot water heating unit 9a. An aqueous medium side switching mechanism 161a that can be performed is provided. The aqueous medium side switching mechanism 161a is a three-way valve.

Further, the heat pump system 1 is provided with a control unit (not shown) that performs the following operations and various controls.
<Operation>
Next, the operation of the heat pump system 1 will be described.
The operation mode of the heat pump system 1 includes a hot water supply operation mode in which the hot water supply operation of the first usage unit 4a (that is, the operation of the hot water storage unit 8a and / or the hot water heating unit 9a) is performed.
Hereinafter, the operation in the hot water supply operation mode of the heat pump system 1 will be described.
-Hot water operation mode-
When the hot water supply operation of the first usage unit 4a is performed, in the heat source side refrigerant circuit 20, the heat source side switching mechanism 23 is in the heat source side evaporation operation state (the state indicated by the broken line of the heat source side switching mechanism 23 in FIG. 1). And the suction return expansion valve 26a is closed. In the aqueous medium circuit 80a, the aqueous medium switching mechanism 161a is switched to a state in which the aqueous medium is supplied to the hot water storage unit 8a and / or the hot water heating unit 9a.

In the heat source side refrigerant circuit 20 in such a state, the low pressure heat source side refrigerant in the refrigeration cycle is sucked into the heat source side compressor 21 through the heat source side suction pipe 21c and compressed to a high pressure in the refrigeration cycle, and then the heat source side refrigerant circuit 20 is cooled. It is discharged to the discharge pipe 21b. The high pressure heat source side refrigerant discharged to the heat source side discharge pipe 21b is separated from the refrigerating machine oil in the oil separator 22a. The refrigerating machine oil separated from the heat source side refrigerant in the oil separator 22a is returned to the heat source side suction pipe 21c through the oil return pipe 22b. The high-pressure heat source side refrigerant from which the refrigerating machine oil is separated is sent from the heat source unit 2 to the gas refrigerant communication tube 14 through the heat source side switching mechanism 23, the second heat source side gas refrigerant tube 23b, and the gas side shut-off valve 30.
The high-pressure heat-source-side refrigerant sent to the gas refrigerant communication tube 14 is sent to the first usage unit 4a. The high-pressure heat-source-side refrigerant sent to the first usage unit 4a is sent to the first usage-side heat exchanger 41a through the first usage-side gas refrigerant tube 54a. The high-pressure heat-source-side refrigerant sent to the first usage-side heat exchanger 41a exchanges heat with the low-pressure usage-side refrigerant in the refrigeration cycle circulating in the usage-side refrigerant circuit 40a in the first usage-side heat exchanger 41a. To dissipate heat. The high-pressure heat-source-side refrigerant radiated in the first usage-side heat exchanger 41a is sent from the first usage unit 4a to the liquid refrigerant communication tube 13 through the first usage-side flow rate adjustment valve 42a and the first usage-side liquid refrigerant tube 45a. It is done.

The heat source side refrigerant sent to the liquid refrigerant communication tube 13 is sent to the heat source unit 2. The heat source side refrigerant sent to the heat source unit 2 is sent to the supercooler 27 through the liquid side shut-off valve 29. The heat source side refrigerant sent to the subcooler 27 is sent to the heat source side expansion valve 25 without performing heat exchange because the heat source side refrigerant does not flow through the suction return pipe 26. The heat source side refrigerant sent to the heat source side expansion valve 25 is depressurized by the heat source side expansion valve 25 to be in a low-pressure gas-liquid two-phase state, and sent to the heat source side heat exchanger 24 through the heat source side liquid refrigerant tube 24a. It is done. The low-pressure refrigerant sent to the heat source side heat exchanger 24 evaporates by exchanging heat with outdoor air supplied by the heat source side fan 32 in the heat source side heat exchanger 24. The low-pressure heat source side refrigerant evaporated in the heat source side heat exchanger 24 is sent to the heat source side accumulator 28 through the first heat source side gas refrigerant tube 23a and the heat source side switching mechanism 23. The low-pressure heat source side refrigerant sent to the heat source side accumulator 28 is again sucked into the heat source side compressor 21 through the heat source side suction pipe 21c.

On the other hand, in the usage-side refrigerant circuit 40a, the low-pressure usage-side refrigerant in the refrigeration cycle circulating in the usage-side refrigerant circuit 40a is heated and evaporated by the heat radiation of the heat source-side refrigerant in the first usage-side heat exchanger 41a. The low-pressure usage-side refrigerant evaporated in the first usage-side heat exchanger 41a is sent to the usage-side accumulator 67a through the second cascade-side gas refrigerant tube 69a. The low-pressure use-side refrigerant sent to the use-side accumulator 67a is sucked into the use-side compressor 62a through the cascade-side suction pipe 71a, compressed to a high pressure in the refrigeration cycle, and then discharged to the cascade-side discharge pipe 70a. . The high-pressure use-side refrigerant discharged to the cascade-side discharge pipe 70a is sent to the refrigerant-water heat exchanger 65a through the first cascade-side gas refrigerant pipe 72a. The high-pressure use-side refrigerant sent to the refrigerant-water heat exchanger 65a radiates heat by exchanging heat with the aqueous medium circulating in the aqueous medium circuit 80a by the circulation pump 43a in the refrigerant-water heat exchanger 65a. The high-pressure use-side refrigerant that has radiated heat in the refrigerant-water heat exchanger 65a is decompressed in the refrigerant-water heat exchange side flow rate control valve 66a to become a low-pressure gas-liquid two-phase state, and passes through the cascade-side liquid refrigerant pipe 68a. Again, it is sent to the 1st utilization side heat exchanger 41a.

In the aqueous medium circuit 80a, the aqueous medium circulating in the aqueous medium circuit 80a is heated by the heat radiation of the use-side refrigerant in the refrigerant-water heat exchanger 65a. The aqueous medium heated in the refrigerant-water heat exchanger 65a is drawn into the circulation pump 43a through the first usage-side water outlet pipe 48a, and after being pressurized, is sent from the first usage unit 4a to the aqueous medium communication pipe 16a. It is done. The aqueous medium sent to the aqueous medium communication pipe 16a is sent to the hot water storage unit 8a and / or the hot water heating unit 9a through the aqueous medium side switching mechanism 161a. The aqueous medium sent to the hot water storage unit 8a exchanges heat with the aqueous medium in the hot water storage tank 81a in the heat exchange coil 82a to radiate heat, thereby heating the aqueous medium in the hot water storage tank 81a. The aqueous medium sent to the hot water heating unit 9a dissipates heat in the heat exchange panel 91a, thereby heating the indoor wall or the like or heating the indoor floor.

Thus, the operation in the hot water supply operation mode for performing the hot water supply operation of the first usage unit 4a is performed.
-Control of the discharge saturation temperature of each refrigerant circuit and control of the degree of supercooling at the outlet of each heat exchanger-
Next, the discharge saturation temperature control of the refrigerant circuits 20 and 40a and the supercooling degree control of the outlets of the heat exchangers 41a and 65a in the hot water supply operation described above will be described.
In the heat pump system 1, as described above, in the first usage-side heat exchanger 41a, the usage-side refrigerant that circulates in the usage-side refrigerant circuit 40a is heated by the heat radiation of the heat-source-side refrigerant that circulates in the heat source-side refrigerant circuit 20. Since the use side refrigerant circuit 40a can obtain a refrigeration cycle having a temperature higher than that of the refrigeration cycle in the heat source side refrigerant circuit 20 using the heat obtained from the heat source side refrigerant, the refrigerant-water A high-temperature aqueous medium can be obtained by the heat radiation of the use-side refrigerant in the heat exchanger 65a. At this time, in order to stably obtain a high-temperature aqueous medium, it is preferable to perform control so that both the refrigeration cycle in the heat source side refrigerant circuit 20 and the refrigeration cycle in the use side refrigerant circuit 40a are stable.

Therefore, in this heat pump system 1, the compressors 21 and 62a of both refrigerant circuits 20 and 40a are both of variable capacity type, and the saturation temperature (that is, the heat source) corresponding to the refrigerant pressure at the discharge of each compressor 21 and 62a. Side discharge saturation temperature Tc1 and use side discharge saturation temperature Tc2) are used as representative values of the refrigerant pressure in each refrigeration cycle so that each discharge saturation temperature Tc1, Tc2 becomes a predetermined target discharge saturation temperature Tc1s, Tc2s. The capacity of the compressors 21 and 62a is controlled.
Here, the heat source side discharge saturation temperature Tc1 is a value obtained by converting the heat source side discharge pressure Pd1, which is the pressure of the heat source side refrigerant in the discharge of the heat source side compressor 21, into a saturation temperature corresponding to this pressure value. The discharge saturation temperature Tc2 is a value obtained by converting the use side discharge pressure Pd2 that is the pressure of the use side refrigerant in the discharge of the use side compressor 62a into a saturation temperature corresponding to this pressure value.

In the heat source side refrigerant circuit 20, when the heat source side discharge saturation temperature Tc1 is lower than the target heat source side discharge saturation temperature Tc1s, the rotation speed (that is, the operating frequency) of the heat source side compressor 21 is increased. When the operation capacity of the heat source side compressor 21 is controlled to be large and the heat source side discharge saturation temperature Tc1 is higher than the target heat source side discharge saturation temperature Tc1s, the rotational speed of the heat source side compressor 21 (that is, the operation frequency). ) Is reduced so that the operation capacity of the heat source side compressor 21 is reduced. In the use side refrigerant circuit 40a, when the use side discharge saturation temperature Tc2 is lower than the target use side discharge saturation temperature Tc2s, the rotation speed (that is, the operating frequency) of the use side compressor 62a is increased. When the operation capacity of the use side compressor 62a is controlled to be large and the use side discharge saturation temperature Tc2 is higher than the target use side discharge saturation temperature Tc2s, the rotation speed (that is, the operation frequency) of the use side compressor 62a. ) Is reduced so that the operation capacity of the use side compressor 62a is reduced.

As a result, the pressure of the heat source side refrigerant flowing through the first usage side refrigerant circuit 41a is stabilized in the heat source side refrigerant circuit 20, and the usage side refrigerant flowing in the refrigerant-water heat exchanger 65a is stabilized in the usage side refrigerant circuit 40a. Since the pressure is stabilized, the state of the refrigeration cycle in both refrigerant circuits 20 and 40a can be stabilized, and a high-temperature aqueous medium can be stably obtained.
At this time, in order to obtain an aqueous medium having a desired temperature, it is preferable to appropriately set the target discharge saturation temperatures Tc1s and Tc2s.
Therefore, in this heat pump system 1, first, a predetermined target aqueous medium outlet temperature Twls, which is a target value of the aqueous medium temperature at the outlet of the refrigerant-water heat exchanger 65a, is set for the usage-side refrigerant circuit 41a. The target use side discharge saturation temperature Tc2s is set as a value that can be varied by the target aqueous medium outlet temperature Twls. Here, for example, when the target aqueous medium outlet temperature Twls is set to 80 ° C., the target usage-side discharge saturation temperature Tc2s is set to 85 ° C., and the target aqueous medium outlet temperature Twls is set to 25 ° C. In such a case, the target use side discharge saturation temperature Tc2s becomes higher as the target aqueous medium outlet temperature Twls is set to a higher temperature, such as setting the target use side discharge saturation temperature Tc2s to 30 ° C. Thus, the function is set in a range of 30 ° C. to 85 ° C. so that the temperature is slightly higher than the target aqueous medium outlet temperature Twls. Thereby, since the target use side discharge saturation temperature Tc2s is appropriately set according to the target aqueous medium outlet temperature Twls, the desired target aqueous medium outlet temperature Tws is easily obtained, and the target aqueous medium outlet temperature Tws is changed. Even in such a case, control with good responsiveness can be performed.

For the heat source side refrigerant circuit 20, the target heat source side discharge saturation temperature Tc1s is set as a value that can be varied by the target use side discharge saturation temperature Tc2s or the target aqueous medium outlet temperature Tws. Here, for example, when the target use side discharge saturation temperature Tc2s or the target aqueous medium outlet temperature Tws is set to 75 ° C. or 80 ° C., the target heat source side discharge saturation temperature Tc1s is set to a temperature range of 35 ° C. to 40 ° C. When the target use side discharge saturation temperature Tc2s or the target aqueous medium outlet temperature Tws is set to 30 ° C. or 25 ° C., the target heat source side discharge saturation temperature Tc1s is set to 10 ° C. to 15 ° C. As the target use side discharge saturation temperature Tc2s or the target aqueous medium outlet temperature Tws is set to a higher temperature, the target heat source side discharge saturation temperature Tc1s also becomes a higher temperature range. And a function set within the range of 10 ° C to 40 ° C so that the temperature range is lower than the target use side discharge saturation temperature Tc2s or the target aqueous medium outlet temperature Tws. There. The target use side discharge saturation temperature Tc2s is preferably set as one temperature as described above for the purpose of accurately obtaining the target aqueous medium outlet temperature Tws, but the target heat source side discharge saturation temperature Tc1s. Is not required to be as strict as the target use-side discharge saturation temperature Tc2, but rather it is preferable to allow a certain temperature range, so it is preferable to set the temperature range as described above. Thereby, since the target heat source side discharge saturation temperature Tc1s is appropriately set according to the target use side discharge saturation temperature Tc2s or the target aqueous medium outlet temperature Tws, according to the state of the refrigeration cycle in the use side refrigerant circuit 40a. The refrigeration cycle in the heat source side refrigerant circuit 20 can be appropriately controlled.

Further, in the heat pump system 1, the first use side flow rate adjustment valve 42a is used as a mechanism for performing main decompression of the heat source side refrigerant flowing through the heat source side refrigerant circuit 20, and the main decompression of the use side refrigerant flowing through the use side refrigerant circuit 40a. A refrigerant-water heat exchange side flow rate adjustment valve 66a is provided as a mechanism for performing the heat source side refrigerant circuit 20, and for the heat source side refrigerant circuit 20, the heat source side refrigerant excess which is the degree of subcooling of the heat source side refrigerant at the outlet of the first usage side heat exchanger 41a is provided. The opening degree of the first usage-side flow rate adjustment valve 42a is controlled so that the degree of cooling SC1 becomes the target heat source side refrigerant subcooling degree SC1s, and the usage-side refrigerant circuit 40a has the refrigerant-water heat exchanger 65a. The degree of opening of the refrigerant-hydrothermal exchange side flow rate adjustment valve 66a is controlled so that the utilization side refrigerant supercooling degree SC2 that is the degree of supercooling of the utilization side refrigerant at the outlet of the refrigerant becomes the target utilization side refrigerant subcooling degree SC2s. It is way.
Here, the heat source side refrigerant subcooling degree SC1 is a value obtained by subtracting the first usage side refrigerant temperature Tsc1 from the heat source side discharge saturation temperature Tc1, and the usage side refrigerant subcooling degree SC2 is cascaded from the usage side discharge saturation temperature Tc2. This is a value obtained by subtracting the side refrigerant temperature Tsc2.

In the heat-source-side refrigerant circuit 20, when the heat-source-side refrigerant subcooling degree SC1 is smaller than the target heat-source-side refrigerant subcooling degree SC1s, the opening degree of the first usage-side flow rate adjustment valve 42a is reduced. When the flow rate of the heat source side refrigerant flowing through the 1 use side heat exchanger 41a is controlled to be small, and the heat source side refrigerant subcool degree SC1 is larger than the target heat source side refrigerant subcool degree SC1s, the first use side flow rate Control is performed so that the flow rate of the heat-source-side refrigerant flowing through the first usage-side heat exchanger 41a is increased by increasing the opening of the control valve 42a. In the use side refrigerant circuit 40a, when the use side refrigerant subcooling degree SC2 is smaller than the target use side refrigerant subcooling degree SC2s, the opening degree of the refrigerant-hydrothermal exchange side flow rate adjustment valve 66a is reduced. If the use-side refrigerant subcooling degree SC2 is greater than the target use-side refrigerant subcooling degree SC2s, the refrigerant-water heat is controlled so that the flow rate of the use-side refrigerant flowing through the refrigerant-water heat exchanger 65a is small. Control is performed such that the flow rate of the use-side refrigerant flowing through the refrigerant-water heat exchanger 65a is increased by increasing the opening degree of the exchange-side flow rate adjustment valve 66a. The target refrigerant subcooling degrees SC1s and SC2s are set in consideration of the design conditions of the heat exchange capacity of the first usage side heat exchanger 41a and the refrigerant-water heat exchanger 65a.

Accordingly, the flow rate of the heat source side refrigerant flowing through the first usage side refrigerant circuit 41a is stabilized in the heat source side refrigerant circuit 20, and the usage side refrigerant flowing in the refrigerant-water heat exchanger 65a is stabilized in the usage side refrigerant circuit 40a. Since the flow rate is stable, the operation can be performed under conditions suitable for the heat exchange capacity of the first usage-side heat exchanger 41a and the refrigerant-water heat exchanger 65a, and the state of the refrigeration cycle in both the refrigerant circuits 20, 40a can be changed. Contributes to stabilization.
Thus, in this heat pump system 1, the pressure and flow rate of the refrigerant in each refrigerant circuit 20, 40a are controlled by the discharge saturation temperature control of each refrigerant circuit 20, 40a and the supercooling degree control of the outlet of each heat exchanger 41a, 65a. As a result, the state of the refrigeration cycle in both refrigerant circuits 20 and 40a can be stabilized, and a high-temperature aqueous medium can be stably obtained.

<Features>
This heat pump system 1 has the following features.
-A-
In the heat pump system 1, in the first usage-side heat exchanger 41a, the usage-side refrigerant circulating in the usage-side refrigerant circuit 40a is heated by the heat radiation of the heat source-side refrigerant circulating in the heat source-side refrigerant circuit 20. Since the use-side refrigerant circuit 40a can obtain a refrigeration cycle having a temperature higher than that of the refrigeration cycle in the heat source-side refrigerant circuit 20 by using heat obtained from the heat source-side refrigerant, the use-side refrigerant circuit 40a in the refrigerant-water heat exchanger 65a A high-temperature aqueous medium can be obtained by heat radiation from the use-side refrigerant.
At this time, as in the heat pump system 1, the use side refrigerant circuit 40a is included in the first use unit 4a, and the first use side heat exchanger 41a functioning as an evaporator of the use side refrigerant is used on the use side. From the viewpoint of the circuit configuration, the length of the refrigerant pipe to the compressor 62a (that is, the total length of the second cascade side gas refrigerant pipe 69a and the cascade side suction pipe 71a) is a short refrigerant pipe of 3 m or less. Since there is a low possibility that the refrigeration oil will be accumulated in a portion of the usage side refrigerant circuit 40a other than the usage side compressor 62a, originally, the amount of the refrigeration oil enclosed in the usage side refrigerant circuit 40a together with the usage side refrigerant is determined. It is thought that it can be reduced.

On the other hand, from the viewpoint of obtaining a high-temperature aqueous medium, as in the heat pump system 1, the pressure corresponding to the saturated gas temperature of 65 ° C. is 2.8 MPa or less, preferably 2 It is preferable to use a high boiling point refrigerant such as a refrigerant of 0.0 MPa or less (that is, a refrigerant having a low-pressure saturation characteristic, here, HFC-134a). When used for the purpose of obtaining an aqueous medium, the use side refrigerant in the gas state dissolved in the refrigerating machine oil increases due to use under high temperature conditions, and as a result, the viscosity of the refrigerating machine oil decreases, and the use side compressor 62a Since the amount of refrigerating machine oil discharged together with the refrigerant increases and there is a risk of insufficient lubrication in the use side compressor 62a, the use side refrigerant circuit 40a and the use side refrigerant It is considered necessary to increase the amount of refrigerating machine oil to be sealed in.

Moreover, when the temperature of the refrigeration oil in the use side compressor 62a is lower than the condensation temperature of the use side refrigerant, the use side refrigerant may condense in the use side compressor 62a, and dilution of the refrigeration oil may occur. However, in particular, in a system for obtaining a high-temperature aqueous medium such as the heat pump system 1, since the condensation temperature of the use-side refrigerant is high, dilution of the refrigerating machine oil is very easy to proceed, and as a result, the viscosity of the refrigerating machine oil is increased. The rate decreases and the amount of refrigerating machine oil discharged from the use side compressor 62a together with the refrigerant increases, which may cause insufficient lubrication in the use side compressor 62a. It is considered necessary to increase the amount of refrigerating machine oil enclosed in the circuit 40a together with the use-side refrigerant. In particular, a high-pressure space (not shown) filled with the heat-source-side refrigerant after being compressed in the compression element is formed in the casing of the usage-side compressor 62a, such as the usage-side compressor 62a in the heat pump system 1. In the structure in which the refrigerating machine oil is stored in the high-pressure space, the use-side refrigerant is easily condensed and the refrigerating machine oil is easily diluted.

As described above, when the amount of the refrigerating machine oil is increased, the refrigerating machine oil discharged with the use side refrigerant discharged from the use side compressor 62a is separated and returned to the suction of the use side compressor 62a. It is preferable to provide a separation mechanism.
However, in use under high-temperature conditions such as the heat pump system 1, as described above, the use-side refrigerant in the gas state dissolved in the refrigeration oil increases, and the dilution of the refrigeration oil easily proceeds. Since the amount of refrigerating machine oil discharged along with the use side refrigerant discharged from the use side compressor 62a also increases, the use side that is returned to the suction of the use side compressor 62a together with the refrigerating machine oil when the oil separation mechanism is provided. There is a possibility that the amount of the refrigerant increases and the operation efficiency is lowered.
Therefore, in this heat pump system 1, the purpose of obtaining a high-temperature aqueous medium (the condensation temperature is high, increasing the amount of the use-side refrigerant in the gas state dissolved in the refrigerating machine oil, and promoting the dilution of the refrigerating machine oil by condensing the use-side refrigerant) And there is a low possibility that the refrigeration oil will be accumulated in a portion of the usage side refrigerant circuit 40a other than the usage side compressor 62a (that is, the usage side refrigerant circuit 40a is included in the first usage unit 4a, and Considering the viewpoint of the circuit configuration that the length of the refrigerant pipe from the first usage side heat exchanger 41a functioning as an evaporator of the side refrigerant to the usage side compressor 62a is a short refrigerant pipe of 3 m or less) Unlike the conventional approach to the amount of refrigerating machine oil, the refrigerating machine oil contained in the use-side refrigerant discharged from the use-side compressor 62a is separated into the use-side refrigerant circuit 40a and used. Without providing an oil separation mechanism for returning to the suction of the compressor 62a, the weight of the use side refrigerant enclosed in the use side refrigerant circuit 40a is 1 of the weight of the refrigerating machine oil enclosed for lubricating the use side compressor. I try to make it from 3 to 3 times.

Thereby, in this heat pump system 1, while allowing the quantity of the use side refrigerant | coolant returned to the suction | inhalation of the use side compressor 62a with refrigerating machine oil to increase, the fall of the operating efficiency by this and the use side compressor 62a inside A high temperature aqueous medium can be obtained while suppressing insufficient lubrication.
In particular, in this heat pump system 1, since HFC-134a is used as the use-side refrigerant, a higher-temperature aqueous medium can be obtained, and the above-described effects are remarkable.
-B-
In this heat pump system 1, in order to stably obtain a high temperature aqueous medium, it is preferable to control so that both the refrigeration cycle in the heat source side refrigerant circuit 20 and the refrigeration cycle in the use side refrigerant circuit 40a are stable. In this heat pump system 1, the compressors 21 and 62a of both refrigerant circuits 20 and 40a are both of variable capacity type, and the saturation temperature corresponding to the refrigerant pressure at the discharge of each compressor 21 and 62a (that is, the heat source side discharge) Using the saturation temperature Tc1 and the use-side discharge saturation temperature Tc2) as representative values of the refrigerant pressure in each refrigeration cycle, each compressor 21, Since the capacity control of 62a is performed, the state of the refrigeration cycle in both refrigerant circuits 20, 40a It can be constant, which makes it possible to stably obtain a high-temperature aqueous medium. Moreover, in the heat pump system 1, the first use side heat exchanger 41a is a heat exchanger that directly transfers heat by heat exchange between the heat source side refrigerant and the use side refrigerant, and the heat source side refrigerant circuit 20 There is little heat loss at the time of giving / receiving to the utilization side refrigerant circuit 40a, and it contributes to obtaining a high temperature aqueous medium.

(1) Modification 1
In the heat pump system 1 described above, since the oil separation mechanism is not provided for the discharge of the use side compressor 62a, the refrigeration oil together with the use side refrigerant is in the refrigerant-water heat exchanger 65a that functions as a heat radiator for the use side refrigerant. In addition, in high-temperature conditions, two-phase separation between the liquid-state use-side refrigerant and the refrigerating machine oil easily occurs in the refrigerant-water heat exchanger 65a. Refrigerating machine oil tends to accumulate in the functioning refrigerant-water heat exchanger 65a. As described above, when the degree of supercooling at the outlet of the refrigerant-water heat exchanger 65a is being controlled, the amount of the usage-side refrigerant in the liquid state corresponding to the usage-side refrigerant supercooling degree SC2 is the refrigerant-water. Since it accumulates in the heat exchanger 65a, the two-phase separation between the use-side refrigerant in the liquid state and the refrigerating machine oil is more likely to occur.

Therefore, in this heat pump system 1, as shown in FIG. 2, when it is determined that the use side compressor 62a is deficient in refrigerating machine oil (step S1), the refrigerant in the refrigerant-water heat exchanger 65a The use-side refrigerant containing the refrigeration oil is in a low temperature condition in which two-phase separation between the use-side refrigerant in the liquid state and the refrigeration oil hardly occurs through the refrigerant-water heat exchange side flow rate adjustment valve 66a and the first use side heat exchanger 41a. An oil recovery operation for returning to the use-side accumulator 67a is performed (step S2).
Here, whether or not the use side compressor 62a is deficient in refrigeration oil is determined by the use side discharge temperature Td2 which is the temperature of the use side refrigerant in the discharge of the use side compressor 62a or the refrigerant-water heat exchanger 65a. This is performed based on the aqueous medium outlet temperature Twl, which is the temperature of the aqueous medium at the outlet. More specifically, an operation in a state where the use side discharge temperature Td2 is higher than a predetermined oil shortage discharge temperature Toc1 and the operation frequency f2 of the use side compressor 62a is higher than a predetermined oil shortage frequency foc1 is performed. When the operation is continuously performed for a predetermined oil shortage operation time to1, or when the aqueous medium outlet temperature Twl is higher than the predetermined oil shortage outlet temperature Toc2, and the operation frequency f2 of the use side compressor 62a is When operation in a state greater than the predetermined oil shortage frequency foc2 is continuously performed for a predetermined oil shortage operation time to2 or longer, it is determined that the use side compressor 62a is short of refrigerating machine oil. I have to. Accordingly, the usage side compressor 62a takes into account the degree of penetration of the usage side refrigerant into the refrigeration oil and the level of two-phase separation between the usage side refrigerant and the refrigeration oil in the refrigerant-water heat exchanger 65a. It is possible to appropriately determine whether or not the refrigerator oil is insufficient in the machine 62a.

In the oil recovery operation (step S2), the refrigerant-water heat exchange side flow rate adjustment valve 66a is fully opened, and the operation frequency f2 of the use side compressor 62a is lower than the oil shortage frequencies foc1 and foc2. The operation frequency foc is set. As a result, the amount of refrigerating machine oil discharged together with the use-side refrigerant from the use-side compressor 62a can be reduced, and the refrigerating machine oil accumulated in the refrigerant-water heat exchanger 65a can be quickly discharged. Moreover, in this heat pump system 1, since the length of the refrigerant pipe from the first usage side heat exchanger 41a functioning as the usage side refrigerant evaporator to the usage side compressor 62a is a short refrigerant pipe of 3 m or less, -Refrigerating machine oil discharged from the water heat exchanger 65a is used promptly without accumulating in the refrigerant pipe from the first use side heat exchanger 41a functioning as a use side refrigerant evaporator to the use side compressor 62a. It can be returned to the side accumulator 67a.

Then, after a predetermined oil recovery operation time toc has elapsed (step S3), the first usage unit 4a is returned to the operation state before the oil recovery operation (step S4).
Thereby, in this heat pump system 1, it is possible to prevent a shortage of refrigerating machine oil in the use side compressor 62a. In addition, during this oil recovery operation, the operation of heating the water refrigerant can be continued by causing the refrigerant-water heat exchanger 65a to function as a radiator of the use-side refrigerant, thereby performing the oil recovery operation. The adverse effect on hot water supply operation can be minimized.
(2) Modification 2
In the above-described heat pump system 1 (see FIG. 1), as shown in FIG. 3, the refrigerant-water heat exchanger 65a functions as a radiator for the usage-side refrigerant and the first usage-side heat exchanger 41a serves as the usage-side refrigerant. Use side heat radiation operation state for functioning as an evaporator of the user and the use side causing the refrigerant-water heat exchanger 65a to function as an evaporator for the use side refrigerant and the first use side heat exchanger 41a to function as a radiator for the use side refrigerant A first use side switching mechanism 64a capable of switching between the evaporation operation states may be further provided in the use side refrigerant circuit 40a.

Here, the first use side switching mechanism 64a is a four-way switching valve, and includes a cascade side discharge pipe 70a, a cascade side suction pipe 71a, a first cascade side gas refrigerant pipe 72a, and a second cascade side gas refrigerant pipe. 69a. The first use side switching mechanism 64a communicates the cascade side discharge pipe 70a and the first cascade side gas refrigerant pipe 72a, and communicates (uses) the second cascade side gas refrigerant pipe 69a and the cascade side suction pipe 71a. Corresponding to the side heat radiation operation state (see the solid line of the first use side switching mechanism 64a in FIG. 17), the cascade side discharge pipe 70a and the second cascade side gas refrigerant pipe 69a are communicated, and the first cascade side gas It is possible to perform switching by connecting the refrigerant pipe 72a and the cascade side suction pipe 71a (corresponding to the use side evaporation operation state, see the broken line of the first use side switching mechanism 64a in FIG. 4). The first usage-side switching mechanism 64a is not limited to the four-way switching valve, and has a function of switching the direction of the usage-side refrigerant flow as described above, for example, by combining a plurality of electromagnetic valves. It may be configured as described above.

In the heat pump system 1 having such a configuration, when it is determined by the operation in the hot water supply operation mode that the heat source side heat exchanger 24 needs to be defrosted, the heat source side switching mechanism 23 is in the heat source side heat radiation operation state. By making the heat source side heat exchanger 24 function as a heat radiator for the heat source side refrigerant, the refrigerant-water heat exchanger 65a is used on the usage side refrigerant by setting the first usage side switching mechanism 64a to the usage side evaporation operation state. It is possible to perform a defrosting operation in which the first usage-side heat exchanger 41a functions as a usage-side refrigerant radiator.
Hereinafter, the operation in the defrosting operation will be described with reference to FIG.
First, it is determined whether or not a predetermined defrosting operation start condition is satisfied (that is, whether or not the heat source side heat exchanger 24 needs to be defrosted) (step S11). Here, whether or not the defrosting operation start condition is satisfied depends on whether or not the defrosting time interval Δtdf (that is, the accumulated operation time from the end of the previous defrosting operation) has reached a predetermined defrosting time interval set value Δtdfs. judge.

And when it determines with satisfy | filling the defrost operation start conditions, the following defrost operations are started (step S12).
When starting the defrosting operation, in the heat source side refrigerant circuit 20, the heat source side switching mechanism 23 is switched to the heat source side heat radiation operation state (the state indicated by the solid line of the heat source side switching mechanism 23 in FIG. 3). In the usage-side refrigerant circuit 40a, the first usage-side switching mechanism 64a is switched to the usage-side evaporation operation state (the state indicated by the broken line of the first usage-side switching mechanism 64a in FIG. 3), and the suction return expansion valve 26a is It becomes a closed state.
In the heat source side refrigerant circuit 20 in such a state, the low pressure heat source side refrigerant in the refrigeration cycle is sucked into the heat source side compressor 21 through the heat source side suction pipe 21c and compressed to a high pressure in the refrigeration cycle, and then the heat source side refrigerant circuit 20 is cooled. It is discharged to the discharge pipe 21b. The high pressure heat source side refrigerant discharged to the heat source side discharge pipe 21b is separated from the refrigerating machine oil in the oil separator 22a. The refrigerating machine oil separated from the heat source side refrigerant in the oil separator 22a is returned to the heat source side suction pipe 21c through the oil return pipe 22b. The high-pressure heat-source-side refrigerant from which the refrigerating machine oil has been separated is sent to the heat-source-side heat exchanger 24 through the heat-source-side switching mechanism 23 and the first heat-source-side gas refrigerant tube 23a. The high-pressure heat-source-side refrigerant sent to the heat-source-side heat exchanger 24 radiates heat by exchanging heat with ice attached to the heat-source-side heat exchanger 24 in the heat-source-side heat exchanger 24. The high-pressure heat-source-side refrigerant that has radiated heat in the heat-source-side heat exchanger is sent to the supercooler 27 through the heat source-side expansion valve 25. Since the heat source side refrigerant sent to the subcooler 27 does not flow through the suction return pipe 26, the heat source unit refrigerant passes through the heat source side liquid refrigerant tube 24a and the liquid side shut-off valve 29 without performing heat exchange. 2 to the liquid refrigerant communication tube 13.

The heat source side refrigerant sent to the liquid refrigerant communication tube 13 is sent to the first usage unit 4a.
The heat-source-side refrigerant sent to the first usage unit 4a is sent to the first usage-side flow rate adjustment valve 42a. The heat-source-side refrigerant sent to the first usage-side flow rate adjustment valve 42a is depressurized in the first usage-side flow rate adjustment valve 42a to become a low-pressure gas-liquid two-phase state, and through the first usage-side liquid refrigerant tube 45a, It is sent to the first usage side heat exchanger 41a. The low-pressure heat-source-side refrigerant sent to the first usage-side heat exchanger 41a exchanges heat with the high-pressure usage-side refrigerant in the refrigeration cycle circulating in the usage-side refrigerant circuit 40a in the first usage-side heat exchanger 41a. Evaporate. The low-pressure heat-source-side refrigerant evaporated in the first usage-side heat exchanger 41a is sent from the first usage unit 4a to the gas refrigerant communication tube 14 through the first usage-side gas refrigerant tube 54a.
The heat source side refrigerant sent from the first usage unit 4 a to the gas refrigerant communication tube 14 is sent to the heat source unit 2. The low-pressure heat source side refrigerant sent to the heat source unit 2 is sent to the heat source side accumulator 28 through the gas side shut-off valve 30, the second heat source side gas refrigerant tube 23b, and the heat source side switching mechanism 23. The low-pressure heat source side refrigerant sent to the heat source side accumulator 28 is again sucked into the heat source side compressor 21 through the heat source side suction pipe 21c.

On the other hand, in the usage-side refrigerant circuit 40a, the high-pressure usage-side refrigerant in the refrigeration cycle that circulates in the usage-side refrigerant circuit 40a is radiated by evaporation of the heat-source-side refrigerant in the first usage-side heat exchanger 41a. The high-pressure use-side refrigerant that has radiated heat in the first use-side heat exchanger 41a is sent to the refrigerant-water heat exchange side flow rate adjustment valve 66a. The high-pressure use-side refrigerant sent to the refrigerant-water heat exchange side flow rate adjustment valve 66a is depressurized by the refrigerant-water heat exchange side flow rate adjustment valve 66a to become a low-pressure gas-liquid two-phase state, and the cascade-side liquid refrigerant. It is sent to the refrigerant-water heat exchanger 65a through the pipe 68a. The low-pressure usage-side refrigerant sent to the refrigerant-water heat exchanger 65a evaporates in the refrigerant-water heat exchanger 65a by exchanging heat with the aqueous medium circulating in the aqueous medium circuit 80a by the circulation pump 43a. The low-pressure usage-side refrigerant evaporated in the refrigerant-water heat exchanger 65a is sent to the usage-side accumulator 67a through the first cascade-side gas refrigerant tube 72a and the first usage-side switching mechanism 64a. The low-pressure use-side refrigerant sent to the use-side accumulator 67a is sucked into the use-side compressor 62a through the cascade-side suction pipe 71a, compressed to a high pressure in the refrigeration cycle, and then discharged to the cascade-side discharge pipe 70a. . The high-pressure use-side refrigerant discharged to the cascade-side discharge pipe 70a is sent again to the first use-side heat exchanger 41a through the first use-side switching mechanism 64a and the second cascade-side gas refrigerant pipe 69a.

In this way, the heat source side heat exchanger 24 functions as a heat source side refrigerant radiator by setting the heat source side switching mechanism 23 to the heat source side heat radiation operation state, and the first usage side switching mechanism 64a is utilized on the usage side evaporation operation. In this state, the refrigerant-water heat exchanger 65a functions as an evaporator for the use side refrigerant, and the first use side heat exchanger 41a serves as a radiator for the use side refrigerant (that is, the evaporator of the heat source side refrigerant). As)) to start functioning defrosting operation.
Then, it is determined whether or not a predetermined defrosting operation end condition is satisfied (that is, whether or not the defrosting of the heat source side heat exchanger 24 is completed) (step S13). Here, whether or not the heat source side heat exchanger temperature Thx has reached a predetermined defrosting completion temperature Thxs or a defrosting operation time tdf that is an elapsed time from the start of the defrosting operation is a predetermined defrosting operation setting time tdfs. It is determined whether or not the defrosting operation end condition is satisfied depending on whether or not it has been reached.

And when it determines with satisfy | filling the defrost operation completion | finish conditions, the process which complete | finishes a defrost operation and returns to hot water supply operation mode is performed (step S14).
Thereby, in this heat pump system 1, when defrosting the heat source side heat exchanger 24, the heat source side heat exchanger 24 is made into the heat source side heat dissipation operation state by putting the heat source side switching mechanism 23 into the heat source side heat dissipation operation state. The refrigerant-water heat exchanger 65a functions as an evaporator of the use side refrigerant by setting the first use side switching mechanism 64a to the use side evaporation operation state, and the first use side heat exchange is performed. Since the heat exchanger 41a is caused to function as a radiator for the usage-side refrigerant, the heat-source-side refrigerant radiated and cooled in the heat-source-side heat exchanger 24 is radiated from the usage-side refrigerant in the first usage-side heat exchanger 41a. The usage-side refrigerant that is heated by the heat and cooled by releasing heat in the first usage-side heat exchanger 41a can be heated by evaporating in the refrigerant-water heat exchanger 65a. Accordingly, the defrosting of the heat source-side heat exchanger 24 can be reliably performed.

Further, in the heat pump system 1 having such a configuration, when oil recovery operation is necessary in the hot water supply operation mode, the first use side switching mechanism 64a is maintained in the use side heat radiation operation state (that is, Without switching, the oil recovery operation of the first modification of the first embodiment can be performed.
(3) Modification 3
In the above-described heat pump system 1 (see FIGS. 1 and 3), one first usage unit 4a is connected to the heat source unit 2 via the refrigerant communication pipes 13 and 14, as shown in FIG. Here, the hot water heating unit, the hot water storage unit, the aqueous medium circuits 80a, 80b, etc. are not shown), and a plurality (here, two) of the first usage units 4a, 4b are connected via the refrigerant communication tubes 13, 14. , Each other may be connected in parallel. Since the configuration of the first usage unit 4b is the same as that of the first usage unit 4a, the configuration of the first usage unit 4b is indicated by a suffix “a” indicating each part of the first usage unit 4a. Subscript “b” is attached instead of “,” and description of each part is omitted.

Thereby, in this heat pump system 1, it can respond to a plurality of places and uses which require heating of an aqueous medium.
(Second Embodiment)
In heat pump system 1 (refer to Drawing 1, Drawing 3, and Drawing 5) in the above-mentioned 1st embodiment and its modification, it is preferred that not only hot water supply operation but indoor heating can be performed.
Therefore, in this heat pump system 200, in the configuration of the heat pump system 1 (see FIG. 1) according to the above-described first embodiment, as shown in FIG. 6, the air medium is functioned by functioning as a heat source side refrigerant radiator. A second use side heat exchanger 101a capable of heating is further provided in the heat source side refrigerant circuit 20. Hereinafter, the configuration of the heat pump system 200 will be described.

<Configuration>
-The entire-
FIG. 6 is a schematic configuration diagram of a heat pump system 200 according to the second embodiment of the present invention. The heat pump system 200 is an apparatus that can perform an operation of heating an aqueous medium using a vapor compression heat pump cycle.
The heat pump system 200 mainly includes a heat source unit 2, a first usage unit 4a, a second usage unit 10a, a liquid refrigerant communication tube 13, a gas refrigerant communication tube 14, a hot water storage unit 8a, and a hot water heating unit 9a. The aqueous medium communication pipe 15a and the aqueous medium communication pipe 16a are provided, and the heat source unit 2, the first usage unit 4a, and the second usage unit 10a are connected via the refrigerant communication tubes 13 and 14. The heat source side refrigerant circuit 20 is configured, the first usage unit 4a constitutes the usage side refrigerant circuit 40a, and the first usage unit 4a, the hot water storage unit 8a, and the hot water heating unit 9a are connected via the aqueous medium communication pipes 15a and 16a. Thus, the aqueous medium circuit 80a is configured. In the heat source side refrigerant circuit 20, HFC-410A, which is a kind of HFC refrigerant, is sealed as a heat source refrigerant, and ester or ether refrigerating machine oil compatible with the HFC refrigerant is used as the heat source. It is enclosed for lubrication of the side compressor 21. Further, HFC-134a, which is a kind of HFC refrigerant, is sealed in the use side refrigerant circuit 40a as a use side refrigerant, and ester or ether type refrigerating machine oil having compatibility with the HFC refrigerant. Is enclosed for lubrication of the use side compressor 62a. In addition, as a use side refrigerant | coolant, from a viewpoint that the refrigerant | coolant advantageous to a high temperature refrigerating cycle is used, the pressure corresponding to saturation gas temperature 65 degreeC is 2.8 Mpa or less at the maximum at a gauge pressure, Preferably, it is 2.0 Mpa. The following refrigerants are preferably used. Moreover, the weight of the utilization side refrigerant | coolant enclosed with the utilization side refrigerant circuit 40a is 1 to 3 times the weight of the refrigerating machine oil enclosed for lubrication of the utilization side compressor 62a. HFC-134a is a kind of refrigerant having such saturation pressure characteristics. Further, water as an aqueous medium circulates in the aqueous medium circuit 80a.

In the following description of the configuration, the heat source unit 2, the first usage unit 4a, the hot water storage unit 8a, the hot water heating unit 9a, and the liquid refrigerant communication having the same configuration as the heat pump system 1 (see FIG. 1) in the first embodiment. About the structure of the pipe | tube 13, the gas refrigerant | coolant connecting pipe 14, and the aqueous medium connecting pipe 15a, 16a, the same code | symbol is attached | subjected and description is abbreviate | omitted and only the structure of the 2nd utilization unit 10a is demonstrated.
-Second usage unit-
The second usage unit 10 a is installed indoors, is connected to the heat source unit 2 via the refrigerant communication tubes 13 and 14, and constitutes a part of the heat source side refrigerant circuit 20.
The second usage unit 10a mainly includes a second usage-side heat exchanger 101a and a second usage-side flow rate adjustment valve 102a.

The second usage-side heat exchanger 101a is a heat exchanger that functions as a heat-source-side refrigerant radiator or evaporator by exchanging heat between the heat-source-side refrigerant and room air as an air medium. A second usage-side liquid refrigerant tube 103a is connected, and a second usage-side gas refrigerant tube 104a is connected to the gas side thereof. A liquid refrigerant communication tube 13 is connected to the second usage side liquid refrigerant tube 103a, and a gas refrigerant communication tube 14 is connected to the second usage side gas refrigerant tube 104a. The air medium that exchanges heat with the heat source side refrigerant in the second usage side heat exchanger 101a is supplied by the usage side fan 105a driven by the usage side fan motor 106a.
The second usage side flow rate adjustment valve 102a is an electric expansion valve capable of varying the flow rate of the heat source side refrigerant flowing through the second usage side heat exchanger 101a by performing opening degree control. It is provided in the refrigerant pipe 103a.

Thus, the second usage unit 10a causes the second usage-side heat exchanger 101a to function as an evaporator of the heat-source-side refrigerant introduced from the liquid refrigerant communication tube 13 when the heat-source-side switching mechanism 23 is in the heat-source-side heat radiation operation state. Thus, the cooling operation in which the heat source side refrigerant evaporated in the second usage side heat exchanger 101a is led out to the gas refrigerant communication tube 14 and the air medium is cooled by the evaporation of the heat source side refrigerant in the second usage side heat exchanger 101a. And the second use side heat exchanger 101a functions as a heat source side refrigerant radiator introduced from the gas refrigerant communication tube 14 in the heat source side evaporation operation state when the heat source side switching mechanism 23 is The heat source side refrigerant radiated in the second usage side heat exchanger 101a is led out to the liquid refrigerant communication tube 13, and the air medium is released by the heat dissipation of the heat source side refrigerant in the second usage side heat exchanger 101a. It becomes possible to perform the heating operation for heating.
Various sensors are provided in the second usage unit 10a. Specifically, the second usage unit 10a is provided with an indoor temperature sensor 107a that detects the indoor temperature Tr.

The heat pump system 200 is provided with a control unit (not shown) that performs the following operations and various controls.
<Operation>
Next, the operation of the heat pump system 200 will be described.
As the operation mode of the heat pump system 200, the hot water supply operation mode in which only the hot water supply operation of the first usage unit 4a (that is, the operation of the hot water storage unit 8a and / or the hot water heating unit 9a) and the cooling operation of the second usage unit 10a are performed. A cooling operation mode for performing the heating operation mode in which only the heating operation of the second usage unit 10a is performed, and a hot water supply and heating operation mode in which the hot water supply operation of the first usage unit 4a is performed and the heating operation of the second usage unit 10a is performed. is there.

Hereinafter, operations in the four operation modes of the heat pump system 200 will be described.
-Hot water operation mode-
When only the hot water supply operation of the first usage unit 4a is performed, in the heat source side refrigerant circuit 20, the heat source side switching mechanism 23 is in the heat source side evaporation operation state (the state indicated by the broken line of the heat source side switching mechanism 23 in FIG. 7). ) And the suction return expansion valve 26a and the second use side flow rate adjustment valve 102a are closed. In the aqueous medium circuit 80a, the aqueous medium switching mechanism 161a is switched to a state in which the aqueous medium is supplied to the hot water storage unit 8a and / or the hot water heating unit 9a.
In the heat source side refrigerant circuit 20 in such a state, the low pressure heat source side refrigerant in the refrigeration cycle is sucked into the heat source side compressor 21 through the heat source side suction pipe 21c and compressed to a high pressure in the refrigeration cycle, and then the heat source side refrigerant circuit 20 is cooled. It is discharged to the discharge pipe 21b. The high pressure heat source side refrigerant discharged to the heat source side discharge pipe 21b is separated from the refrigerating machine oil in the oil separator 22a. The refrigerating machine oil separated from the heat source side refrigerant in the oil separator 22a is returned to the heat source side suction pipe 21c through the oil return pipe 22b. The high-pressure heat source side refrigerant from which the refrigerating machine oil is separated is sent from the heat source unit 2 to the gas refrigerant communication tube 14 through the heat source side switching mechanism 23, the second heat source side gas refrigerant tube 23b, and the gas side shut-off valve 30.

The high-pressure heat-source-side refrigerant sent to the gas refrigerant communication tube 14 is sent to the first usage unit 4a. The high-pressure heat-source-side refrigerant sent to the first usage unit 4a is sent to the first usage-side heat exchanger 41a through the first usage-side gas refrigerant tube 54a. The high-pressure heat-source-side refrigerant sent to the first usage-side heat exchanger 41a exchanges heat with the low-pressure usage-side refrigerant in the refrigeration cycle circulating in the usage-side refrigerant circuit 40a in the first usage-side heat exchanger 41a. To dissipate heat. The high-pressure heat-source-side refrigerant radiated in the first usage-side heat exchanger 41a is sent from the first usage unit 4a to the liquid refrigerant communication tube 13 through the first usage-side flow rate adjustment valve 42a and the first usage-side liquid refrigerant tube 45a. It is done.
The heat source side refrigerant sent to the liquid refrigerant communication tube 13 is sent to the heat source unit 2. The heat source side refrigerant sent to the heat source unit 2 is sent to the supercooler 27 through the liquid side closing valve 29. The heat source side refrigerant sent to the subcooler 27 is sent to the heat source side expansion valve 25 without performing heat exchange because the heat source side refrigerant does not flow through the suction return pipe 26. The heat source side refrigerant sent to the heat source side expansion valve 25 is depressurized by the heat source side expansion valve 25 to be in a low-pressure gas-liquid two-phase state, and sent to the heat source side heat exchanger 24 through the heat source side liquid refrigerant tube 24a. It is done. The low-pressure refrigerant sent to the heat source side heat exchanger 24 evaporates by exchanging heat with outdoor air supplied by the heat source side fan 32 in the heat source side heat exchanger 24. The low-pressure heat source side refrigerant evaporated in the heat source side heat exchanger 24 is sent to the heat source side accumulator 28 through the first heat source side gas refrigerant tube 23a and the heat source side switching mechanism 23. The low-pressure heat source side refrigerant sent to the heat source side accumulator 28 is again sucked into the heat source side compressor 21 through the heat source side suction pipe 21c.

On the other hand, in the usage-side refrigerant circuit 40a, the low-pressure usage-side refrigerant in the refrigeration cycle circulating in the usage-side refrigerant circuit 40a is heated and evaporated by the heat radiation of the heat source-side refrigerant in the first usage-side heat exchanger 41a. The low-pressure usage-side refrigerant evaporated in the first usage-side heat exchanger 41a is sent to the usage-side accumulator 67a through the second cascade-side gas refrigerant tube 69a. The low-pressure use-side refrigerant sent to the use-side accumulator 67a is sucked into the use-side compressor 62a through the cascade-side suction pipe 71a, compressed to a high pressure in the refrigeration cycle, and then discharged to the cascade-side discharge pipe 70a. . The high-pressure use-side refrigerant discharged to the cascade-side discharge pipe 70a is sent to the refrigerant-water heat exchanger 65a through the first cascade-side gas refrigerant pipe 72a. The high-pressure use-side refrigerant sent to the refrigerant-water heat exchanger 65a radiates heat by exchanging heat with the aqueous medium circulating in the aqueous medium circuit 80a by the circulation pump 43a in the refrigerant-water heat exchanger 65a. The high-pressure use-side refrigerant that has radiated heat in the refrigerant-water heat exchanger 65a is decompressed in the refrigerant-water heat exchange side flow rate control valve 66a to become a low-pressure gas-liquid two-phase state, and passes through the cascade-side liquid refrigerant pipe 68a. Again, it is sent to the 1st utilization side heat exchanger 41a.

In the aqueous medium circuit 80a, the aqueous medium circulating in the aqueous medium circuit 80a is heated by the heat radiation of the use-side refrigerant in the refrigerant-water heat exchanger 65a. The aqueous medium heated in the refrigerant-water heat exchanger 65a is drawn into the circulation pump 43a through the first usage-side water outlet pipe 48a, and after being pressurized, is sent from the first usage unit 4a to the aqueous medium communication pipe 16a. It is done. The aqueous medium sent to the aqueous medium communication pipe 16a is sent to the hot water storage unit 8a and / or the hot water heating unit 9a through the aqueous medium side switching mechanism 161a. The aqueous medium sent to the hot water storage unit 8a exchanges heat with the aqueous medium in the hot water storage tank 81a in the heat exchange coil 82a to radiate heat, thereby heating the aqueous medium in the hot water storage tank 81a. The aqueous medium sent to the hot water heating unit 9a dissipates heat in the heat exchange panel 91a, thereby heating the indoor wall or the like or heating the indoor floor.

Thus, the operation in the hot water supply operation mode in which only the hot water supply operation of the first usage unit 4a is performed is performed.
-Cooling operation mode-
When only the cooling operation of the second usage unit 10a is performed, in the heat source side refrigerant circuit 20, the heat source side switching mechanism 23 is in the heat source side heat dissipation operation state (the state shown by the solid line of the heat source side switching mechanism 23 in FIG. 7). ) And the first usage-side flow rate adjustment valve 42a is closed.
In the heat source side refrigerant circuit 20 in such a state, the low pressure heat source side refrigerant in the refrigeration cycle is sucked into the heat source side compressor 21 through the heat source side suction pipe 21c and compressed to a high pressure in the refrigeration cycle, and then the heat source side refrigerant circuit 20 is cooled. It is discharged to the discharge pipe 21b. The high pressure heat source side refrigerant discharged to the heat source side discharge pipe 21b is separated from the refrigerating machine oil in the oil separator 22a. The refrigerating machine oil separated from the heat source side refrigerant in the oil separator 22a is returned to the heat source side suction pipe 21c through the oil return pipe 22b. The high-pressure heat-source-side refrigerant from which the refrigerating machine oil has been separated is sent to the heat-source-side heat exchanger 24 through the heat-source-side switching mechanism 23 and the first heat-source-side gas refrigerant tube 23a. The high-pressure heat-source-side refrigerant sent to the heat-source-side heat exchanger 24 radiates heat by exchanging heat with outdoor air supplied by the heat-source-side fan 32 in the heat source-side heat exchanger 24. The high-pressure heat-source-side refrigerant that has radiated heat in the heat-source-side heat exchanger is sent to the supercooler 27 through the heat source-side expansion valve 25. The heat source side refrigerant sent to the subcooler 27 is cooled so as to be in a supercooled state by exchanging heat with the heat source side refrigerant branched from the heat source side liquid refrigerant tube 24a to the suction return tube 26. The heat source side refrigerant flowing through the suction return pipe 26 is returned to the heat source side suction pipe 21c. The heat source side refrigerant cooled in the subcooler 27 is sent from the heat source unit 2 to the liquid refrigerant communication tube 13 through the heat source side liquid refrigerant tube 24a and the liquid side shut-off valve 29.

The high-pressure heat source side refrigerant sent to the liquid refrigerant communication tube 13 is sent to the second usage unit 10a. The high-pressure heat-source-side refrigerant sent to the second usage unit 10a is sent to the second usage-side flow rate adjustment valve 102a. The high-pressure heat-source-side refrigerant sent to the second usage-side flow rate adjustment valve 102a is depressurized by the second usage-side flow rate adjustment valve 102a to become a low-pressure gas-liquid two-phase state, and the second usage-side liquid refrigerant tube 103a. To the second usage side heat exchanger 101a. The low-pressure heat source side refrigerant sent to the second usage side heat exchanger 101a evaporates by exchanging heat with the air medium supplied by the usage side fan 105a in the second usage side heat exchanger 101a. Cool the room. The low-pressure heat-source-side refrigerant evaporated in the second usage-side heat exchanger 101a is sent from the second usage unit 10a to the gas refrigerant communication tube 14 through the second usage-side gas refrigerant tube 104a.

The low-pressure heat source side refrigerant sent to the gas refrigerant communication tube 14 is sent to the heat source unit 2. The low-pressure heat source side refrigerant sent to the heat source unit 2 is sent to the heat source side accumulator 28 through the gas side shut-off valve 30, the second heat source side gas refrigerant tube 23b, and the heat source side switching mechanism 23. The low-pressure heat source side refrigerant sent to the heat source side accumulator 28 is again sucked into the heat source side compressor 21 through the heat source side suction pipe 21c.
In this manner, the operation in the cooling operation mode in which only the cooling operation of the second usage unit 10a is performed is performed.
-Heating operation mode-
When only the heating operation of the second usage unit 10a is performed, in the heat source side refrigerant circuit 20, the heat source side switching mechanism 23 is in the heat source side heat radiation operation state (the state indicated by the broken line of the heat source side switching mechanism 23 in FIG. 7). ), And the suction return expansion valve 26a and the first usage-side flow rate adjustment valve 42a are closed.

In the heat source side refrigerant circuit 20 in such a state, the low pressure heat source side refrigerant in the refrigeration cycle is sucked into the heat source side compressor 21 through the heat source side suction pipe 21c and compressed to a high pressure in the refrigeration cycle, and then the heat source side refrigerant circuit 20 is cooled. It is discharged to the discharge pipe 21b. The high pressure heat source side refrigerant discharged to the heat source side discharge pipe 21b is separated from the refrigerating machine oil in the oil separator 22a. The refrigerating machine oil separated from the heat source side refrigerant in the oil separator 22a is returned to the heat source side suction pipe 21c through the oil return pipe 22b. The high-pressure heat source side refrigerant from which the refrigerating machine oil is separated is sent from the heat source unit 2 to the gas refrigerant communication tube 14 through the heat source side switching mechanism 23, the second heat source side gas refrigerant tube 23b, and the gas side shut-off valve 30.
The high-pressure heat-source-side refrigerant sent to the gas refrigerant communication tube 14 is sent to the second usage unit 10a. The high-pressure heat-source-side refrigerant sent to the second usage unit 10a is sent to the second usage-side heat exchanger 101a through the second usage-side gas refrigerant tube 104a. The high-pressure heat-source-side refrigerant sent to the second usage-side heat exchanger 101a performs heat exchange with the air medium supplied by the usage-side fan 105a in the second usage-side heat exchanger 101a, thereby radiating heat. , Heating the room. The high-pressure heat-source-side refrigerant radiated in the second usage-side heat exchanger 101a is sent from the second usage unit 10a to the liquid refrigerant communication tube 13 through the second usage-side flow rate adjustment valve 102a and the second usage-side liquid refrigerant tube 103a. It is done.

The heat source side refrigerant sent to the liquid refrigerant communication tube 13 is sent to the heat source unit 2. The heat source side refrigerant sent to the heat source unit 2 is sent to the supercooler 27 through the liquid side shut-off valve 29. The heat source side refrigerant sent to the subcooler 27 is sent to the heat source side expansion valve 25 without performing heat exchange because the heat source side refrigerant does not flow through the suction return pipe 26. The heat source side refrigerant sent to the heat source side expansion valve 25 is depressurized by the heat source side expansion valve 25 to be in a low-pressure gas-liquid two-phase state, and sent to the heat source side heat exchanger 24 through the heat source side liquid refrigerant tube 24a. It is done. The low-pressure refrigerant sent to the heat source side heat exchanger 24 evaporates by exchanging heat with outdoor air supplied by the heat source side fan 32 in the heat source side heat exchanger 24. The low-pressure heat source side refrigerant evaporated in the heat source side heat exchanger 24 is sent to the heat source side accumulator 28 through the first heat source side gas refrigerant tube 23a and the heat source side switching mechanism 23. The low-pressure heat source side refrigerant sent to the heat source side accumulator 28 is again sucked into the heat source side compressor 21 through the heat source side suction pipe 21c.

Thus, the operation | movement in the heating operation mode which performs only the heating operation of the 2nd utilization unit 10a is performed.
-Hot water heating / heating mode-
When the hot water supply operation of the first usage unit 4a is performed and the heating operation of the second usage unit 10a is performed, in the heat source side refrigerant circuit 20, the heat source side switching mechanism 23 is in the heat source side evaporation operation state (the heat source side in FIG. 7). (The state indicated by the broken line of the switching mechanism 23), and the suction return expansion valve 26a is closed. In the aqueous medium circuit 80a, the aqueous medium switching mechanism 161a is switched to a state in which the aqueous medium is supplied to the hot water storage unit 8a and / or the hot water heating unit 9a.
In the heat source side refrigerant circuit 20 in such a state, the low pressure heat source side refrigerant in the refrigeration cycle is sucked into the heat source side compressor 21 through the heat source side suction pipe 21c and compressed to a high pressure in the refrigeration cycle, and then the heat source side refrigerant circuit 20 is cooled. It is discharged to the discharge pipe 21b. The high pressure heat source side refrigerant discharged to the heat source side discharge pipe 21b is separated from the refrigerating machine oil in the oil separator 22a. The refrigerating machine oil separated from the heat source side refrigerant in the oil separator 22a is returned to the heat source side suction pipe 21c through the oil return pipe 22b. The high-pressure heat source side refrigerant from which the refrigerating machine oil is separated is sent from the heat source unit 2 to the gas refrigerant communication tube 14 through the heat source side switching mechanism 23, the second heat source side gas refrigerant tube 23b, and the gas side shut-off valve 30.

The high-pressure heat-source-side refrigerant sent to the gas refrigerant communication tube 14 is sent to the first usage unit 4a and the second usage unit 10a.
The high-pressure heat-source-side refrigerant sent to the second usage unit 10a is sent to the second usage-side heat exchanger 101a through the second usage-side gas refrigerant tube 104a. The high-pressure heat-source-side refrigerant sent to the second usage-side heat exchanger 101a performs heat exchange with the air medium supplied by the usage-side fan 105a in the second usage-side heat exchanger 101a, thereby radiating heat. , Heating the room. The high-pressure heat-source-side refrigerant radiated in the second usage-side heat exchanger 101a is sent from the second usage unit 10a to the liquid refrigerant communication tube 13 through the second usage-side flow rate adjustment valve 102a and the second usage-side liquid refrigerant tube 103a. It is done.
The high-pressure heat-source-side refrigerant sent to the first usage unit 4a is sent to the first usage-side heat exchanger 41a through the first usage-side gas refrigerant tube 54a. The high-pressure heat-source-side refrigerant sent to the first usage-side heat exchanger 41a exchanges heat with the low-pressure usage-side refrigerant in the refrigeration cycle circulating in the usage-side refrigerant circuit 40a in the first usage-side heat exchanger 41a. To dissipate heat. The high-pressure heat-source-side refrigerant radiated in the first usage-side heat exchanger 41a is sent from the first usage unit 4a to the liquid refrigerant communication tube 13 through the first usage-side flow rate adjustment valve 42a and the first usage-side liquid refrigerant tube 45a. It is done.

The heat-source-side refrigerant sent from the second usage unit 10a and the first usage unit 4a to the liquid refrigerant communication tube 13 merges in the liquid refrigerant communication tube 13 and is sent to the heat source unit 2. The heat source side refrigerant sent to the heat source unit 2 is sent to the supercooler 27 through the liquid side shut-off valve 29. The heat source side refrigerant sent to the subcooler 27 is sent to the heat source side expansion valve 25 without performing heat exchange because the heat source side refrigerant does not flow through the suction return pipe 26. The heat source side refrigerant sent to the heat source side expansion valve 25 is depressurized by the heat source side expansion valve 25 to be in a low-pressure gas-liquid two-phase state, and sent to the heat source side heat exchanger 24 through the heat source side liquid refrigerant tube 24a. It is done. The low-pressure refrigerant sent to the heat source side heat exchanger 24 evaporates by exchanging heat with outdoor air supplied by the heat source side fan 32 in the heat source side heat exchanger 24. The low-pressure heat source side refrigerant evaporated in the heat source side heat exchanger 24 is sent to the heat source side accumulator 28 through the first heat source side gas refrigerant tube 23a and the heat source side switching mechanism 23. The low-pressure heat source side refrigerant sent to the heat source side accumulator 28 is again sucked into the heat source side compressor 21 through the heat source side suction pipe 21c.

On the other hand, in the usage-side refrigerant circuit 40a, the low-pressure usage-side refrigerant in the refrigeration cycle circulating in the usage-side refrigerant circuit 40a is heated and evaporated by the heat radiation of the heat source-side refrigerant in the first usage-side heat exchanger 41a. The low-pressure usage-side refrigerant evaporated in the first usage-side heat exchanger 41a is sent to the usage-side accumulator 67a through the second cascade-side gas refrigerant tube 69a. The low-pressure use-side refrigerant sent to the use-side accumulator 67a is sucked into the use-side compressor 62a through the cascade-side suction pipe 71a, compressed to a high pressure in the refrigeration cycle, and then discharged to the cascade-side discharge pipe 70a. . The high-pressure use-side refrigerant discharged to the cascade-side discharge pipe 70a is sent to the refrigerant-water heat exchanger 65a through the first cascade-side gas refrigerant pipe 72a. The high-pressure use-side refrigerant sent to the refrigerant-water heat exchanger 65a radiates heat by exchanging heat with the aqueous medium circulating in the aqueous medium circuit 80a by the circulation pump 43a in the refrigerant-water heat exchanger 65a. The high-pressure use-side refrigerant that has radiated heat in the refrigerant-water heat exchanger 65a is decompressed in the refrigerant-water heat exchange side flow rate control valve 66a to become a low-pressure gas-liquid two-phase state, and passes through the cascade-side liquid refrigerant pipe 68a. Again, it is sent to the 1st utilization side heat exchanger 41a.

In the aqueous medium circuit 80a, the aqueous medium circulating in the aqueous medium circuit 80a is heated by the heat radiation of the use-side refrigerant in the refrigerant-water heat exchanger 65a. The aqueous medium heated in the refrigerant-water heat exchanger 65a is drawn into the circulation pump 43a through the first usage-side water outlet pipe 48a, and after being pressurized, is sent from the first usage unit 4a to the aqueous medium communication pipe 16a. It is done. The aqueous medium sent to the aqueous medium communication pipe 16a is sent to the hot water storage unit 8a and / or the hot water heating unit 9a through the aqueous medium side switching mechanism 161a. The aqueous medium sent to the hot water storage unit 8a exchanges heat with the aqueous medium in the hot water storage tank 81a in the heat exchange coil 82a to radiate heat, thereby heating the aqueous medium in the hot water storage tank 81a. The aqueous medium sent to the hot water heating unit 9a dissipates heat in the heat exchange panel 91a, thereby heating the indoor wall or the like or heating the indoor floor.

In this way, the operation in the hot water supply and heating operation mode in which the hot water supply operation of the first usage unit 4a is performed and the heating operation of the second usage unit 10a is performed is performed.
The heat pump system 1 in the first embodiment (see FIG. 1) is also used in the configuration of the heat pump system 200 in which the first usage unit 4a for hot water supply operation and the second usage unit 10a for air conditioning operation are connected to the heat source unit 2. ), The discharge saturation temperature control of the refrigerant circuits 20 and 40a and the supercooling degree control of the outlets of the heat exchangers 41a and 65a are performed.
Thereby, in this heat pump system 200, while being able to acquire the same operation effect as heat pump system 1 in a 1st embodiment, the 2nd use unit 10a which has the 2nd use side heat exchanger 101a is provided, Operation for heating the air medium by heat radiation of the heat source side refrigerant in the second usage side heat exchanger 101a (here, heating operation) and operation for cooling the air medium by evaporation of the heat source side refrigerant in the second usage side heat exchanger 101a (Here, cooling operation) can be performed, so that not only the aqueous medium heated in the first use side heat exchanger 41a and the use side refrigerant circuit 40a is used for hot water supply, The air medium heated in the utilization heat exchanger 101a can be used for room heating.

(1) Modification 1
Even in a configuration in which the first usage unit 4a for hot water supply operation and the second usage unit 10a for air conditioning operation are connected to the heat source unit 2 as in the above-described heat pump system 200 (see FIG. 6), the first embodiment is also used. Similarly to the heat pump system 1 (see FIG. 1) of the first modification, since the oil separation mechanism is not provided for the discharge of the use side compressor 62a, the refrigeration oil together with the use side refrigerant serves as a radiator for the use side refrigerant. The refrigerant-water heat exchanger 65a is likely to be introduced into the functioning refrigerant-water heat exchanger 65a, and two-phase separation between the liquid-state use-side refrigerant and the refrigerating machine oil is likely to occur in the refrigerant-water heat exchanger 65a under high temperature conditions. Therefore, the refrigerating machine oil tends to accumulate in the refrigerant-water heat exchanger 65a that functions as a radiator for the use-side refrigerant. In addition, when the degree of supercooling at the outlet of the refrigerant-water heat exchanger 65a is being controlled, the amount of liquid-side usage-side refrigerant corresponding to the usage-side refrigerant subcooling degree SC2 is within the refrigerant-water heat exchanger 65a. Therefore, the two-phase separation between the use-side refrigerant in the liquid state and the refrigerating machine oil is more likely to occur.

Therefore, in the heat pump system 200, the same oil recovery operation control (see FIG. 2) as that in the heat pump system 1 (see FIG. 1) in the first embodiment is performed.
Thereby, it is possible to prevent a shortage of refrigerating machine oil in the use side compressor 62a. In addition, during this oil recovery operation, the operation of heating the water refrigerant can be continued by causing the refrigerant-water heat exchanger 65a to function as a radiator of the use-side refrigerant, thereby performing the oil recovery operation. The adverse effect on the hot water supply operation and hot water supply / heating operation can be minimized.
(2) Modification 2
Even in the configuration in which the first use unit 4a for hot water supply operation and the second use unit 10a for air conditioning operation are connected to the heat source unit 2 as in the heat pump system 200 (see FIG. 6) described above, the first embodiment is also used. As in the heat pump system 1 (see FIG. 3) in the second modified example, as shown in FIG. 7, the refrigerant-water heat exchanger 65a functions as a heat radiator for the use-side refrigerant and the first use-side heat exchanger The utilization side heat radiation operation state in which 41a functions as a utilization side refrigerant evaporator, the refrigerant-water heat exchanger 65a functions as a utilization side refrigerant evaporator, and the first utilization side heat exchanger 41a serves as a utilization side refrigerant radiator. The use side refrigerant circuit 40a may be further provided with a first use side switching mechanism 64a capable of switching between the use side evaporation operation state to function as.

In the heat pump system 200 having such a configuration, when it is determined that defrosting of the heat source side heat exchanger 24 is necessary by operations in the hot water supply operation mode, the heating operation mode, or the hot water supply heating operation mode, the heat source side By setting the switching mechanism 23 to the heat source side heat radiation operation state, the heat source side heat exchanger 24 functions as a heat source side refrigerant radiator and the second usage side heat exchanger 101a functions as a heat source side refrigerant evaporator. In addition, by setting the first usage side switching mechanism 64a to the usage side evaporation operation state, the refrigerant-water heat exchanger 65a functions as an evaporator of the usage side refrigerant, and the first usage side heat exchanger 41a is used on the usage side. A defrosting operation that functions as a refrigerant radiator can be performed.
Hereinafter, the operation in the defrosting operation will be described with reference to FIG.
First, it is determined whether or not a predetermined defrosting operation start condition is satisfied (that is, whether or not the heat source side heat exchanger 24 needs to be defrosted) (step S11). Here, whether or not the defrosting operation start condition is satisfied depends on whether or not the defrosting time interval Δtdf (that is, the accumulated operation time from the end of the previous defrosting operation) has reached a predetermined defrosting time interval set value Δtdfs. judge.

And when it determines with satisfy | filling the defrost operation start conditions, the following defrost operations are started (step S12).
When starting the defrosting operation, in the heat source side refrigerant circuit 20, the heat source side switching mechanism 23 is switched to the heat source side heat radiation operation state (the state indicated by the solid line of the heat source side switching mechanism 23 in FIG. 7). In the usage-side refrigerant circuit 40a, the first usage-side switching mechanism 64a is switched to the usage-side evaporation operation state (the state indicated by the broken line of the first usage-side switching mechanism 64a in FIG. 7), and the suction return expansion valve 26a is It becomes a closed state.
In the heat source side refrigerant circuit 20 in such a state, the low pressure heat source side refrigerant in the refrigeration cycle is sucked into the heat source side compressor 21 through the heat source side suction pipe 21c and compressed to a high pressure in the refrigeration cycle, and then the heat source side refrigerant circuit 20 is cooled. It is discharged to the discharge pipe 21b. The high pressure heat source side refrigerant discharged to the heat source side discharge pipe 21b is separated from the refrigerating machine oil in the oil separator 22a. The refrigerating machine oil separated from the heat source side refrigerant in the oil separator 22a is returned to the heat source side suction pipe 21c through the oil return pipe 22b. The high-pressure heat-source-side refrigerant from which the refrigerating machine oil has been separated is sent to the heat-source-side heat exchanger 24 through the heat-source-side switching mechanism 23 and the first heat-source-side gas refrigerant tube 23a. The high-pressure heat-source-side refrigerant sent to the heat-source-side heat exchanger 24 radiates heat by exchanging heat with ice attached to the heat-source-side heat exchanger 24 in the heat-source-side heat exchanger 24. The high-pressure heat-source-side refrigerant that has radiated heat in the heat-source-side heat exchanger is sent to the supercooler 27 through the heat source-side expansion valve 25. Since the heat source side refrigerant sent to the subcooler 27 does not flow through the suction return pipe 26, the heat source unit refrigerant passes through the heat source side liquid refrigerant tube 24a and the liquid side shut-off valve 29 without performing heat exchange. 2 to the liquid refrigerant communication tube 13.

The heat-source-side refrigerant sent to the liquid refrigerant communication tube 13 branches in the liquid refrigerant communication tube 13 and is sent to the first usage unit 4a and the second usage unit 10a.
The heat-source-side refrigerant sent to the second usage unit 10a is sent to the second usage-side flow rate adjustment valve 102a. The heat-source-side refrigerant sent to the second usage-side flow rate adjustment valve 102a is depressurized by the second usage-side flow rate adjustment valve 102a to become a low-pressure gas-liquid two-phase state, and through the second usage-side liquid refrigerant tube 103a, It is sent to the second usage side heat exchanger 101a. The low-pressure heat-source-side refrigerant sent to the second usage-side heat exchanger 101a evaporates by exchanging heat with the air medium supplied by the usage-side fan 105a in the second usage-side heat exchanger 101a. The low-pressure heat-source-side refrigerant evaporated in the second usage-side heat exchanger 101a is sent from the second usage unit 10a to the gas refrigerant communication tube 14 through the second usage-side gas refrigerant tube 104a.

The heat-source-side refrigerant sent to the first usage unit 4a is sent to the first usage-side flow rate adjustment valve 42a. The heat-source-side refrigerant sent to the first usage-side flow rate adjustment valve 42a is depressurized in the first usage-side flow rate adjustment valve 42a to become a low-pressure gas-liquid two-phase state, and through the first usage-side liquid refrigerant tube 45a, It is sent to the first usage side heat exchanger 41a. The low-pressure heat-source-side refrigerant sent to the first usage-side heat exchanger 41a exchanges heat with the high-pressure usage-side refrigerant in the refrigeration cycle circulating in the usage-side refrigerant circuit 40a in the first usage-side heat exchanger 41a. Evaporate. The low-pressure heat-source-side refrigerant evaporated in the first usage-side heat exchanger 41a is sent from the first usage unit 4a to the gas refrigerant communication tube 14 through the first usage-side gas refrigerant tube 54a.
The heat-source-side refrigerant sent from the second usage unit 10a and the first usage unit 4a to the gas refrigerant communication tube 14 merges in the gas refrigerant communication tube 14 and is sent to the heat source unit 2. The low-pressure heat source side refrigerant sent to the heat source unit 2 is sent to the heat source side accumulator 28 through the gas side shut-off valve 30, the second heat source side gas refrigerant tube 23b, and the heat source side switching mechanism 23. The low-pressure heat source side refrigerant sent to the heat source side accumulator 28 is again sucked into the heat source side compressor 21 through the heat source side suction pipe 21c.

On the other hand, in the usage-side refrigerant circuit 40a, the high-pressure usage-side refrigerant in the refrigeration cycle that circulates in the usage-side refrigerant circuit 40a is radiated by evaporation of the heat-source-side refrigerant in the first usage-side heat exchanger 41a. The high-pressure use-side refrigerant that has radiated heat in the first use-side heat exchanger 41a is sent to the refrigerant-water heat exchange side flow rate adjustment valve 66a. The high-pressure use-side refrigerant sent to the refrigerant-water heat exchange side flow rate adjustment valve 66a is depressurized by the refrigerant-water heat exchange side flow rate adjustment valve 66a to become a low-pressure gas-liquid two-phase state, and the cascade-side liquid refrigerant. It is sent to the refrigerant-water heat exchanger 65a through the pipe 68a. The low-pressure usage-side refrigerant sent to the refrigerant-water heat exchanger 65a evaporates in the refrigerant-water heat exchanger 65a by exchanging heat with the aqueous medium circulating in the aqueous medium circuit 80a by the circulation pump 43a. The low-pressure usage-side refrigerant evaporated in the refrigerant-water heat exchanger 65a is sent to the usage-side accumulator 67a through the first cascade-side gas refrigerant tube 72a and the first usage-side switching mechanism 64a. The low-pressure use-side refrigerant sent to the use-side accumulator 67a is sucked into the use-side compressor 62a through the cascade-side suction pipe 71a, compressed to a high pressure in the refrigeration cycle, and then discharged to the cascade-side discharge pipe 70a. . The high-pressure use-side refrigerant discharged to the cascade-side discharge pipe 70a is sent again to the first use-side heat exchanger 41a through the first use-side switching mechanism 64a and the second cascade-side gas refrigerant pipe 69a.

In this way, the heat source side heat exchanger 24 is made to function as a heat source side refrigerant radiator by setting the heat source side switching mechanism 23 to the heat source side heat radiation operation state, and the second usage side heat exchanger 101a is set to the heat source side. The refrigerant-water heat exchanger 65a functions as a usage-side refrigerant evaporator by causing the first usage-side switching mechanism 64a to be in the usage-side evaporation operation state, while functioning as a refrigerant evaporator, and the first usage side A defrosting operation for causing the heat exchanger 41a to function as a heat radiator for the use side refrigerant (that is, as an evaporator for the heat source side refrigerant) is started.
Then, it is determined whether or not a predetermined defrosting operation end condition is satisfied (that is, whether or not the defrosting of the heat source side heat exchanger 24 is completed) (step S13). Here, whether or not the heat source side heat exchanger temperature Thx has reached a predetermined defrosting completion temperature Thxs or a defrosting operation time tdf that is an elapsed time from the start of the defrosting operation is a predetermined defrosting operation setting time tdfs. It is determined whether or not the defrosting operation end condition is satisfied depending on whether or not it has been reached.

And when it determines with satisfy | filling the defrost operation completion | finish conditions, the process which complete | finishes a defrost operation and returns to hot water supply operation mode is performed (step S14).
Thus, in the heat pump system 200, when the heat source side heat exchanger 24 is defrosted, the heat source side heat exchanger 24 is placed in the heat source side heat dissipation operation state by setting the heat source side switching mechanism 23 to the heat source side heat radiator 24. The refrigerant-water heat exchanger 65a functions as an evaporator of the use side refrigerant by setting the first use side switching mechanism 64a to the use side evaporation operation state, and the first use side heat exchange is performed. Since the heat exchanger 41a is caused to function as a radiator for the usage-side refrigerant, the heat-source-side refrigerant radiated and cooled in the heat-source-side heat exchanger 24 is radiated from the usage-side refrigerant in the first usage-side heat exchanger 41a. It is possible to heat the use-side refrigerant that has been heated by the first heat-side heat exchanger 41a and is radiated and cooled in the first use-side heat exchanger 41a by evaporating in the refrigerant-water heat exchanger 65a. Thus, it is possible to reliably perform defrosting of the heat source-side heat exchanger 24. In addition, since the second usage-side heat exchanger 101a also functions as a heat source-side refrigerant evaporator, the defrosting operation time tdf can be shortened, and the air cooled in the second usage unit 10a. It can suppress that the temperature of a medium becomes low.

Further, in the heat pump system 200 having such a configuration, when the oil recovery operation is necessary in the hot water supply operation mode or the hot water supply / heating operation mode, the first use side switching mechanism 64a is maintained in the use side heat radiation operation state. The oil recovery operation of the first modification of the first embodiment can be performed as it is (that is, without switching).
(3) Modification 3
In the above-described heat pump system 200 (see FIGS. 6 and 7), one first usage unit 4a and one second usage unit 10a are connected to the heat source unit 2 via the refrigerant communication tubes 13 and 14. 8 to 10 (here, illustration of the hot water heating unit, the hot water storage unit, the aqueous medium circuit 80a, 80b, etc. is omitted), a plurality of (here, two) first usage units 4a, 4b is connected to each other in parallel via the refrigerant communication pipes 13 and 14, and / or a plurality (here, two) of the second usage units 10a and 10b are connected to the refrigerant communication pipe 13 , 14 may be connected to each other in parallel. Since the configuration of the first usage unit 4b is the same as that of the first usage unit 4a, the configuration of the first usage unit 4b is indicated by a suffix “a” indicating each part of the first usage unit 4a. Subscript “b” is attached instead of “,” and description of each part is omitted. In addition, since the configuration of the second usage unit 10b is the same as the configuration of the second usage unit 10a, the configuration of the second usage unit 10b is indicated by a subscript “a” indicating each part of the second usage unit 10a. Subscript “b” is attached instead of “,” and description of each part is omitted.

Thereby, in these heat pump systems 200, it can respond to a plurality of places and uses which require heating of an aqueous medium, and can respond to a plurality of places and uses which require cooling of an air medium.
(4) Modification 4
In the above-described heat pump system 200 (see FIGS. 6 to 10), the second usage-side flow rate adjustment valves 102a and 102b are provided in the second usage units 10a and 10b, but as shown in FIG. Then, the hot water heating unit, the hot water storage unit, the aqueous medium circuit 80a, etc. are not shown), the second usage side flow rate adjustment valves 102a, 102b are omitted from the second usage units 10a, 10b, and the second usage side flow rate adjustment valve is omitted. An expansion valve unit 17 having 102a and 102b may be provided.

(Third embodiment)
In the heat pump system 200 (see FIG. 6 to FIG. 11) in the second embodiment and the modified example described above, the hot water supply operation of the first usage unit 4a cannot be performed and the cooling operation of the second usage unit 10a cannot be performed. If such a hot water supply cooling operation can be performed, the hot water supply operation can be performed in an operation state in which the cooling operation is performed in summer or the like, which is preferable.
Therefore, in this heat pump system 300, in the configuration of the heat pump system 200 (see FIG. 6) according to the second embodiment described above, as shown in FIG. 12, the second usage side heat exchanger 101a is made to evaporate the heat source side refrigerant. The air medium is cooled by functioning as a heater, and the hot water supply and cooling operation, which is an operation for heating the aqueous medium, can be performed by causing the first use side heat exchanger 41a to function as a heat radiator of the heat source side refrigerant. I have to. Hereinafter, the configuration of the heat pump system 300 will be described.

<Configuration>
-The entire-
FIG. 12 is a schematic configuration diagram of a heat pump system 300 according to the third embodiment of the present invention. The heat pump system 300 is an apparatus capable of performing an operation for heating an aqueous medium using a vapor compression heat pump cycle.
The heat pump system 300 mainly includes a heat source unit 2, a first usage unit 4a, a second usage unit 10a, a discharge refrigerant communication tube 12, a liquid refrigerant communication tube 13, a gas refrigerant communication tube 14, and a hot water storage unit 8a. A hot water heating unit 9a, an aqueous medium communication pipe 15a, and an aqueous medium communication pipe 16a. The heat source unit 2, the first usage unit 4a, and the second usage unit 10a are connected to the refrigerant communication pipes 12, 13, 14, the heat source side refrigerant circuit 20 is constituted, the first usage unit 4a constitutes the usage side refrigerant circuit 40a, and the first usage unit 4a, the hot water storage unit 8a, and the hot water heating unit 9a are provided. The aqueous medium circuit 80a is configured by being connected via the aqueous medium communication pipes 15a and 16a. In the heat source side refrigerant circuit 20, HFC-410A, which is a kind of HFC refrigerant, is sealed as a heat source refrigerant, and ester or ether refrigerating machine oil compatible with the HFC refrigerant is used as the heat source. It is enclosed for lubrication of the side compressor 21. Further, HFC-134a, which is a kind of HFC refrigerant, is sealed in the use side refrigerant circuit 40a as a use side refrigerant, and ester or ether type refrigerating machine oil having compatibility with the HFC refrigerant. Is enclosed for lubrication of the use side compressor 62a. In addition, as a use side refrigerant | coolant, from a viewpoint that the refrigerant | coolant advantageous to a high temperature refrigerating cycle is used, the pressure corresponding to saturation gas temperature 65 degreeC is 2.8 Mpa or less at the maximum at a gauge pressure, Preferably, it is 2.0 Mpa. The following refrigerants are preferably used. Moreover, the weight of the utilization side refrigerant | coolant enclosed with the utilization side refrigerant circuit 40a is 1 to 3 times the weight of the refrigerating machine oil enclosed for lubrication of the utilization side compressor 62a. HFC-134a is a kind of refrigerant having such saturation pressure characteristics. Further, water as an aqueous medium circulates in the aqueous medium circuit 80a.

In the following description of the configuration, the second usage unit 10a, the hot water storage unit 8a, the hot water heating unit 9a, the liquid refrigerant communication tube 13, and the gas having the same configuration as the heat pump system 200 (see FIG. 6) in the second embodiment. About the structure of the refrigerant | coolant communication pipe | tube 14 and the aqueous medium communication pipe | tube 15a, 16a, the same code | symbol is attached | subjected and description is abbreviate | omitted and only the structure of the heat-source unit 2, the discharge refrigerant | coolant communication pipe | tube 12, and the 1st utilization unit 4a is demonstrated. I do.
-Heat source unit-
The heat source unit 2 is installed outdoors and is connected to the utilization units 4 a and 10 a via the refrigerant communication pipes 12, 13 and 14 and constitutes a part of the heat source side refrigerant circuit 20.
The heat source unit 2 mainly includes a heat source side compressor 21, an oil separation mechanism 22, a heat source side switching mechanism 23, a heat source side heat exchanger 24, a heat source side expansion mechanism 25, a suction return pipe 26, and a supercooling. A heat source side accumulator 28, a liquid side closing valve 29, a gas side closing valve 30, and a discharge side closing valve 31.

Here, the discharge side shut-off valve 31 is formed between the heat source side discharge branch pipe 21d branched from the heat source side discharge pipe 21b connecting the discharge of the heat source side compressor 21 and the heat source side switching mechanism 23 and the gas refrigerant communication pipe 14. It is the valve provided in the connection part.
The heat source unit 2 is the same as the heat pump system 200 (see FIG. 6) in the second embodiment except for the configuration having the discharge side shut-off valve 31 and the heat source side discharge branch pipe 21d. The same reference numerals are given and the description is omitted.
-Discharge refrigerant communication tube-
The discharge refrigerant communication pipe 12 is connected to the heat source side discharge branch pipe 21d via the discharge side closing valve 31, and the heat source side switching mechanism 23 is on the heat source side in both the heat source side heat radiation operation state and the heat source side evaporation operation state. This is a refrigerant pipe capable of leading the heat source side refrigerant out of the heat source unit 2 from the discharge of the compressor 21.

-First use unit-
The first usage unit 4a is installed indoors, is connected to the heat source unit 2 and the second usage unit 10a via the refrigerant communication pipes 12 and 13, and constitutes a part of the heat source side refrigerant circuit 20. Yes. Moreover, the 1st utilization unit 4a comprises the utilization side refrigerant circuit 40a. Furthermore, the 1st utilization unit 4a is connected to the hot water storage unit 8a and the hot water heating unit 9a via the aqueous medium communication pipes 15a and 16a, and constitutes a part of the aqueous medium circuit 80a.
The first usage unit 4a mainly includes a first usage-side heat exchanger 41a, a first usage-side flow rate adjustment valve 42a, a usage-side compressor 62a, a refrigerant-water heat exchanger 65a, and a refrigerant-hydrothermal exchange. It has a side flow rate adjustment valve 66a, a use side accumulator 67a, and a circulation pump 43a.

Here, the first use side heat exchanger 41a is connected to the gas refrigerant communication pipe 14 like the heat pump system 200 (see FIG. 6) in the second embodiment on the gas side of the flow path through which the heat source side refrigerant flows. Instead of the first use side gas refrigerant pipe 54a, a first use side discharge refrigerant pipe 46a to which the discharge refrigerant communication pipe 12 is connected is connected. The first use side discharge refrigerant pipe 46a allows the flow of the heat source side refrigerant from the discharge refrigerant communication pipe 12 toward the first use side heat exchanger 41a, and is discharged from the first use side heat exchanger 41a to the discharge refrigerant communication pipe 12. A first usage-side discharge check valve 49a that prohibits the flow of the heat source side refrigerant toward the first side is provided.
Note that the usage unit 4a has a configuration in which the first usage-side discharge refrigerant pipe 46a is connected in place of the first usage-side gas refrigerant pipe 54a except for the heat pump system 200 in the second embodiment (see FIG. 6), the same reference numerals are used here and the description thereof is omitted.

The heat pump system 300 is provided with a control unit (not shown) that performs the following operations and various controls.
<Operation>
Next, the operation of the heat pump system 300 will be described.
The operation modes of the heat pump system 300 include a hot water supply operation mode in which only the hot water supply operation of the first usage unit 4a (that is, the operation of the hot water storage unit 8a and / or the hot water heating unit 9a) and the cooling operation of the second usage unit 10a are performed. A cooling operation mode for performing the heating operation mode for performing only the heating operation of the second usage unit 10a, a hot water supply / heating operation mode for performing the hot water supply operation of the first usage unit 4a and performing the heating operation of the second usage unit 10a, There is a hot water supply / cooling operation mode in which the hot water supply operation of the first usage unit 4a is performed and the cooling operation of the second usage unit 10a is performed.

Hereinafter, operations in the five operation modes of the heat pump system 300 will be described.
-Hot water operation mode-
When only the hot water supply operation of the first usage unit 4a is performed, in the heat source side refrigerant circuit 20, the heat source side switching mechanism 23 is in the heat source side evaporation operation state (the state shown by the broken line of the heat source side switching mechanism 23 in FIG. 12). ) And the suction return expansion valve 26a and the second use side flow rate adjustment valve 102a are closed. In the aqueous medium circuit 80a, the aqueous medium switching mechanism 161a is switched to a state in which the aqueous medium is supplied to the hot water storage unit 8a and / or the hot water heating unit 9a.
In the heat source side refrigerant circuit 20 in such a state, the low pressure heat source side refrigerant in the refrigeration cycle is sucked into the heat source side compressor 21 through the heat source side suction pipe 21c and compressed to a high pressure in the refrigeration cycle, and then the heat source side refrigerant circuit 20 is cooled. It is discharged to the discharge pipe 21b. The high pressure heat source side refrigerant discharged to the heat source side discharge pipe 21b is separated from the refrigerating machine oil in the oil separator 22a. The refrigerating machine oil separated from the heat source side refrigerant in the oil separator 22a is returned to the heat source side suction pipe 21c through the oil return pipe 22b. The high-pressure heat-source-side refrigerant from which the refrigeration oil has been separated is sent from the heat-source unit 2 to the discharge refrigerant communication tube 12 through the heat-source-side discharge branch pipe 21d and the discharge-side shut-off valve 31.

The high-pressure heat source side refrigerant sent to the discharge refrigerant communication tube 12 is sent to the first usage unit 4a. The high-pressure heat-source-side refrigerant sent to the first usage unit 4a is sent to the first usage-side heat exchanger 41a through the first usage-side discharge refrigerant tube 46a and the first usage-side discharge check valve 49a. The high-pressure heat-source-side refrigerant sent to the first usage-side heat exchanger 41a exchanges heat with the low-pressure usage-side refrigerant in the refrigeration cycle circulating in the usage-side refrigerant circuit 40a in the first usage-side heat exchanger 41a. To dissipate heat. The high-pressure heat-source-side refrigerant radiated in the first usage-side heat exchanger 41a is sent from the first usage unit 4a to the liquid refrigerant communication tube 13 through the first usage-side flow rate adjustment valve 42a and the first usage-side liquid refrigerant tube 45a. It is done.
The heat source side refrigerant sent to the liquid refrigerant communication tube 13 is sent to the heat source unit 2. The heat source side refrigerant sent to the heat source unit 2 is sent to the supercooler 27 through the liquid side closing valve 29. The heat source side refrigerant sent to the subcooler 27 is sent to the heat source side expansion valve 25 without performing heat exchange because the heat source side refrigerant does not flow through the suction return pipe 26. The heat source side refrigerant sent to the heat source side expansion valve 25 is depressurized by the heat source side expansion valve 25 to be in a low-pressure gas-liquid two-phase state, and sent to the heat source side heat exchanger 24 through the heat source side liquid refrigerant tube 24a. It is done. The low-pressure refrigerant sent to the heat source side heat exchanger 24 evaporates by exchanging heat with outdoor air supplied by the heat source side fan 32 in the heat source side heat exchanger 24. The low-pressure heat source side refrigerant evaporated in the heat source side heat exchanger 24 is sent to the heat source side accumulator 28 through the first heat source side gas refrigerant tube 23a and the heat source side switching mechanism 23. The low-pressure heat source side refrigerant sent to the heat source side accumulator 28 is again sucked into the heat source side compressor 21 through the heat source side suction pipe 21c.

On the other hand, in the usage-side refrigerant circuit 40a, the low-pressure usage-side refrigerant in the refrigeration cycle circulating in the usage-side refrigerant circuit 40a is heated and evaporated by the heat radiation of the heat source-side refrigerant in the first usage-side heat exchanger 41a. The low-pressure usage-side refrigerant evaporated in the first usage-side heat exchanger 41a is sent to the usage-side accumulator 67a through the second cascade-side gas refrigerant tube 69a. The low-pressure use-side refrigerant sent to the use-side accumulator 67a is sucked into the use-side compressor 62a through the cascade-side suction pipe 71a, compressed to a high pressure in the refrigeration cycle, and then discharged to the cascade-side discharge pipe 70a. . The high-pressure use-side refrigerant discharged to the cascade-side discharge pipe 70a is sent to the refrigerant-water heat exchanger 65a through the first cascade-side gas refrigerant pipe 72a. The high-pressure use-side refrigerant sent to the refrigerant-water heat exchanger 65a radiates heat by exchanging heat with the aqueous medium circulating in the aqueous medium circuit 80a by the circulation pump 43a in the refrigerant-water heat exchanger 65a. The high-pressure use-side refrigerant that has radiated heat in the refrigerant-water heat exchanger 65a is decompressed in the refrigerant-water heat exchange side flow rate control valve 66a to become a low-pressure gas-liquid two-phase state, and passes through the cascade-side liquid refrigerant pipe 68a. Again, it is sent to the 1st utilization side heat exchanger 41a.

In the aqueous medium circuit 80a, the aqueous medium circulating in the aqueous medium circuit 80a is heated by the heat radiation of the use-side refrigerant in the refrigerant-water heat exchanger 65a. The aqueous medium heated in the refrigerant-water heat exchanger 65a is drawn into the circulation pump 43a through the first usage-side water outlet pipe 48a, and after being pressurized, is sent from the first usage unit 4a to the aqueous medium communication pipe 16a. It is done. The aqueous medium sent to the aqueous medium communication pipe 16a is sent to the hot water storage unit 8a and / or the hot water heating unit 9a through the aqueous medium side switching mechanism 161a. The aqueous medium sent to the hot water storage unit 8a exchanges heat with the aqueous medium in the hot water storage tank 81a in the heat exchange coil 82a to radiate heat, thereby heating the aqueous medium in the hot water storage tank 81a. The aqueous medium sent to the hot water heating unit 9a dissipates heat in the heat exchange panel 91a, thereby heating the indoor wall or the like or heating the indoor floor.

Thus, the operation in the hot water supply operation mode in which only the hot water supply operation of the first usage unit 4a is performed is performed.
-Cooling operation mode-
When only the cooling operation of the second usage unit 10a is performed, in the heat source side refrigerant circuit 20, the heat source side switching mechanism 23 is in the heat source side heat radiation operation state (the state shown by the solid line of the heat source side switching mechanism 23 in FIG. 12). ) And the first usage-side flow rate adjustment valve 42a is closed.
In the heat source side refrigerant circuit 20 in such a state, the low pressure heat source side refrigerant in the refrigeration cycle is sucked into the heat source side compressor 21 through the heat source side suction pipe 21c and compressed to a high pressure in the refrigeration cycle, and then the heat source side refrigerant circuit 20 is cooled. It is discharged to the discharge pipe 21b. The high pressure heat source side refrigerant discharged to the heat source side discharge pipe 21b is separated from the refrigerating machine oil in the oil separator 22a. The refrigerating machine oil separated from the heat source side refrigerant in the oil separator 22a is returned to the heat source side suction pipe 21c through the oil return pipe 22b. The high-pressure heat-source-side refrigerant from which the refrigerating machine oil has been separated is sent to the heat-source-side heat exchanger 24 through the heat-source-side switching mechanism 23 and the first heat-source-side gas refrigerant tube 23a. The high-pressure heat-source-side refrigerant sent to the heat-source-side heat exchanger 24 radiates heat by exchanging heat with outdoor air supplied by the heat-source-side fan 32 in the heat source-side heat exchanger 24. The high-pressure heat-source-side refrigerant that has radiated heat in the heat-source-side heat exchanger is sent to the supercooler 27 through the heat source-side expansion valve 25. The heat source side refrigerant sent to the subcooler 27 is cooled so as to be in a supercooled state by exchanging heat with the heat source side refrigerant branched from the heat source side liquid refrigerant tube 24a to the suction return tube 26. The heat source side refrigerant flowing through the suction return pipe 26 is returned to the heat source side suction pipe 21c. The heat source side refrigerant cooled in the subcooler 27 is sent from the heat source unit 2 to the liquid refrigerant communication tube 13 through the heat source side liquid refrigerant tube 24a and the liquid side shut-off valve 29.

The high-pressure heat source side refrigerant sent to the liquid refrigerant communication tube 13 is sent to the second usage unit 10a. The high-pressure heat-source-side refrigerant sent to the second usage unit 10a is sent to the second usage-side flow rate adjustment valve 102a. The high-pressure heat-source-side refrigerant sent to the second usage-side flow rate adjustment valve 102a is depressurized by the second usage-side flow rate adjustment valve 102a to become a low-pressure gas-liquid two-phase state, and the second usage-side liquid refrigerant tube 103a. To the second usage side heat exchanger 101a. The low-pressure heat source side refrigerant sent to the second usage side heat exchanger 101a evaporates by exchanging heat with the air medium supplied by the usage side fan 105a in the second usage side heat exchanger 101a. Cool the room. The low-pressure heat-source-side refrigerant evaporated in the second usage-side heat exchanger 101a is sent from the second usage unit 10a to the gas refrigerant communication tube 14 through the second usage-side gas refrigerant tube 104a.

The low-pressure heat source side refrigerant sent to the gas refrigerant communication tube 14 is sent to the heat source unit 2. The low-pressure heat source side refrigerant sent to the heat source unit 2 is sent to the heat source side accumulator 28 through the gas side shut-off valve 30, the second heat source side gas refrigerant tube 23b, and the heat source side switching mechanism 23. The low-pressure heat source side refrigerant sent to the heat source side accumulator 28 is again sucked into the heat source side compressor 21 through the heat source side suction pipe 21c.
In this manner, the operation in the cooling operation mode in which only the cooling operation of the second usage unit 10a is performed is performed.
-Heating operation mode-
When only the heating operation of the second usage unit 10a is performed, in the heat source side refrigerant circuit 20, the heat source side switching mechanism 23 is in the heat source side heat radiation operation state (the state indicated by the broken line of the heat source side switching mechanism 23 in FIG. 12). ), And the suction return expansion valve 26a and the first usage-side flow rate adjustment valve 42a are closed.

In the heat source side refrigerant circuit 20 in such a state, the low pressure heat source side refrigerant in the refrigeration cycle is sucked into the heat source side compressor 21 through the heat source side suction pipe 21c and compressed to a high pressure in the refrigeration cycle, and then the heat source side refrigerant circuit 20 is cooled. It is discharged to the discharge pipe 21b. The high pressure heat source side refrigerant discharged to the heat source side discharge pipe 21b is separated from the refrigerating machine oil in the oil separator 22a. The refrigerating machine oil separated from the heat source side refrigerant in the oil separator 22a is returned to the heat source side suction pipe 21c through the oil return pipe 22b. The high-pressure heat source side refrigerant from which the refrigerating machine oil is separated is sent from the heat source unit 2 to the gas refrigerant communication tube 14 through the heat source side switching mechanism 23, the second heat source side gas refrigerant tube 23b, and the gas side shut-off valve 30.
The high-pressure heat-source-side refrigerant sent to the gas refrigerant communication tube 14 is sent to the second usage unit 10a. The high-pressure heat-source-side refrigerant sent to the second usage unit 10a is sent to the second usage-side heat exchanger 101a through the second usage-side gas refrigerant tube 104a. The high-pressure heat-source-side refrigerant sent to the second usage-side heat exchanger 101a performs heat exchange with the air medium supplied by the usage-side fan 105a in the second usage-side heat exchanger 101a, thereby radiating heat. , Heating the room. The high-pressure heat-source-side refrigerant radiated in the second usage-side heat exchanger 101a is sent from the second usage unit 10a to the liquid refrigerant communication tube 13 through the second usage-side flow rate adjustment valve 102a and the second usage-side liquid refrigerant tube 103a. It is done.

The heat source side refrigerant sent to the liquid refrigerant communication tube 13 is sent to the heat source unit 2. The heat source side refrigerant sent to the heat source unit 2 is sent to the supercooler 27 through the liquid side shut-off valve 29. The heat source side refrigerant sent to the subcooler 27 is sent to the heat source side expansion valve 25 without performing heat exchange because the heat source side refrigerant does not flow through the suction return pipe 26. The heat source side refrigerant sent to the heat source side expansion valve 25 is depressurized by the heat source side expansion valve 25 to be in a low-pressure gas-liquid two-phase state, and sent to the heat source side heat exchanger 24 through the heat source side liquid refrigerant tube 24a. It is done. The low-pressure refrigerant sent to the heat source side heat exchanger 24 evaporates by exchanging heat with outdoor air supplied by the heat source side fan 32 in the heat source side heat exchanger 24. The low-pressure heat source side refrigerant evaporated in the heat source side heat exchanger 24 is sent to the heat source side accumulator 28 through the first heat source side gas refrigerant tube 23a and the heat source side switching mechanism 23. The low-pressure heat source side refrigerant sent to the heat source side accumulator 28 is again sucked into the heat source side compressor 21 through the heat source side suction pipe 21c.

Thus, the operation | movement in the heating operation mode which performs only the heating operation of the 2nd utilization unit 10a is performed.
-Hot water heating / heating mode-
When the hot water supply operation of the first usage unit 4a is performed and the heating operation of the second usage unit 10a is performed, in the heat source side refrigerant circuit 20, the heat source side switching mechanism 23 is in the heat source side evaporation operation state (the heat source side in FIG. 12). (The state indicated by the broken line of the switching mechanism 23), and the suction return expansion valve 26a is closed. In the aqueous medium circuit 80a, the aqueous medium switching mechanism 161a is switched to a state in which the aqueous medium is supplied to the hot water storage unit 8a and / or the hot water heating unit 9a.
In the heat source side refrigerant circuit 20 in such a state, the low pressure heat source side refrigerant in the refrigeration cycle is sucked into the heat source side compressor 21 through the heat source side suction pipe 21c and compressed to a high pressure in the refrigeration cycle, and then the heat source side refrigerant circuit 20 is cooled. It is discharged to the discharge pipe 21b. The high pressure heat source side refrigerant discharged to the heat source side discharge pipe 21b is separated from the refrigerating machine oil in the oil separator 22a. The refrigerating machine oil separated from the heat source side refrigerant in the oil separator 22a is returned to the heat source side suction pipe 21c through the oil return pipe 22b. A part of the high-pressure heat source side refrigerant from which the refrigerating machine oil has been separated is sent from the heat source unit 2 to the discharge refrigerant communication pipe 12 through the heat source side discharge branch pipe 21d and the discharge side shut-off valve 31, and the rest is used as the heat source. It is sent from the heat source unit 2 to the gas refrigerant communication pipe 14 through the side switching mechanism 23, the second heat source side gas refrigerant pipe 23 b, and the gas side closing valve 30.

The high-pressure heat-source-side refrigerant sent to the gas refrigerant communication tube 14 is sent to the second usage unit 10a. The high-pressure heat-source-side refrigerant sent to the second usage unit 10a is sent to the second usage-side heat exchanger 101a through the second usage-side gas refrigerant tube 104a. The high-pressure heat-source-side refrigerant sent to the second usage-side heat exchanger 101a performs heat exchange with the air medium supplied by the usage-side fan 105a in the second usage-side heat exchanger 101a, thereby radiating heat. , Heating the room. The high-pressure heat-source-side refrigerant radiated in the second usage-side heat exchanger 101a is sent from the second usage unit 10a to the liquid refrigerant communication tube 13 through the second usage-side flow rate adjustment valve 102a and the second usage-side liquid refrigerant tube 103a. It is done.
The high-pressure heat source side refrigerant sent to the discharge refrigerant communication tube 12 is sent to the first usage unit 4a. The high-pressure heat-source-side refrigerant sent to the first usage unit 4a is sent to the first usage-side heat exchanger 41a through the first usage-side discharge refrigerant tube 46a and the first usage-side discharge check valve 49a. The high-pressure heat-source-side refrigerant sent to the first usage-side heat exchanger 41a exchanges heat with the low-pressure usage-side refrigerant in the refrigeration cycle circulating in the usage-side refrigerant circuit 40a in the first usage-side heat exchanger 41a. To dissipate heat. The high-pressure heat-source-side refrigerant radiated in the first usage-side heat exchanger 41a is sent from the first usage unit 4a to the liquid refrigerant communication tube 13 through the first usage-side flow rate adjustment valve 42a and the first usage-side liquid refrigerant tube 45a. It is done.

The heat-source-side refrigerant sent from the second usage unit 10a and the first usage unit 4a to the liquid refrigerant communication tube 13 merges in the liquid refrigerant communication tube 13 and is sent to the heat source unit 2. The heat source side refrigerant sent to the heat source unit 2 is sent to the supercooler 27 through the liquid side shut-off valve 29. The heat source side refrigerant sent to the subcooler 27 is sent to the heat source side expansion valve 25 without performing heat exchange because the heat source side refrigerant does not flow through the suction return pipe 26. The heat source side refrigerant sent to the heat source side expansion valve 25 is depressurized by the heat source side expansion valve 25 to be in a low-pressure gas-liquid two-phase state, and sent to the heat source side heat exchanger 24 through the heat source side liquid refrigerant tube 24a. It is done. The low-pressure refrigerant sent to the heat source side heat exchanger 24 evaporates by exchanging heat with outdoor air supplied by the heat source side fan 32 in the heat source side heat exchanger 24. The low-pressure heat source side refrigerant evaporated in the heat source side heat exchanger 24 is sent to the heat source side accumulator 28 through the first heat source side gas refrigerant tube 23a and the heat source side switching mechanism 23. The low-pressure heat source side refrigerant sent to the heat source side accumulator 28 is again sucked into the heat source side compressor 21 through the heat source side suction pipe 21c.

On the other hand, in the usage-side refrigerant circuit 40a, the low-pressure usage-side refrigerant in the refrigeration cycle circulating in the usage-side refrigerant circuit 40a is heated and evaporated by the heat radiation of the heat source-side refrigerant in the first usage-side heat exchanger 41a. The low-pressure usage-side refrigerant evaporated in the first usage-side heat exchanger 41a is sent to the usage-side accumulator 67a through the second cascade-side gas refrigerant tube 69a. The low-pressure use-side refrigerant sent to the use-side accumulator 67a is sucked into the use-side compressor 62a through the cascade-side suction pipe 71a, compressed to a high pressure in the refrigeration cycle, and then discharged to the cascade-side discharge pipe 70a. . The high-pressure use-side refrigerant discharged to the cascade-side discharge pipe 70a is sent to the refrigerant-water heat exchanger 65a through the first cascade-side gas refrigerant pipe 72a. The high-pressure use-side refrigerant sent to the refrigerant-water heat exchanger 65a radiates heat by exchanging heat with the aqueous medium circulating in the aqueous medium circuit 80a by the circulation pump 43a in the refrigerant-water heat exchanger 65a. The high-pressure use-side refrigerant that has radiated heat in the refrigerant-water heat exchanger 65a is decompressed in the refrigerant-water heat exchange side flow rate control valve 66a to become a low-pressure gas-liquid two-phase state, and passes through the cascade-side liquid refrigerant pipe 68a. Again, it is sent to the 1st utilization side heat exchanger 41a.

In the aqueous medium circuit 80a, the aqueous medium circulating in the aqueous medium circuit 80a is heated by the heat radiation of the use-side refrigerant in the refrigerant-water heat exchanger 65a. The aqueous medium heated in the refrigerant-water heat exchanger 65a is drawn into the circulation pump 43a through the first usage-side water outlet pipe 48a, and after being pressurized, is sent from the first usage unit 4a to the aqueous medium communication pipe 16a. It is done. The aqueous medium sent to the aqueous medium communication pipe 16a is sent to the hot water storage unit 8a and / or the hot water heating unit 9a through the aqueous medium side switching mechanism 161a. The aqueous medium sent to the hot water storage unit 8a exchanges heat with the aqueous medium in the hot water storage tank 81a in the heat exchange coil 82a to radiate heat, thereby heating the aqueous medium in the hot water storage tank 81a. The aqueous medium sent to the hot water heating unit 9a dissipates heat in the heat exchange panel 91a, thereby heating the indoor wall or the like or heating the indoor floor.

In this way, the operation in the hot water supply and heating operation mode in which the hot water supply operation of the first usage unit 4a is performed and the heating operation of the second usage unit 10a is performed is performed.
-Hot water supply / cooling operation mode-
When the hot water supply operation of the first usage unit 4a is performed and the cooling operation of the second usage unit 10a is performed, in the heat source side refrigerant circuit 20, the heat source side switching mechanism 23 is in the heat source side heat radiation operation state (the heat source side in FIG. 12). It is switched to the state indicated by the solid line of the switching mechanism 23). In the aqueous medium circuit 80a, the aqueous medium switching mechanism 161a is switched to a state of supplying the aqueous medium to the hot water storage unit 8a.
In the heat source side refrigerant circuit 20 in such a state, the low pressure heat source side refrigerant in the refrigeration cycle is sucked into the heat source side compressor 21 through the heat source side suction pipe 21c and compressed to a high pressure in the refrigeration cycle, and then discharged from the heat source side. It is discharged to the tube 21b. The high pressure heat source side refrigerant discharged to the heat source side discharge pipe 21b is separated from the refrigerating machine oil in the oil separator 22a. The refrigerating machine oil separated from the heat source side refrigerant in the oil separator 22a is returned to the heat source side suction pipe 21c through the oil return pipe 22b. A part of the high-pressure heat source side refrigerant from which the refrigerating machine oil is separated is sent from the heat source unit 2 to the discharge refrigerant communication pipe 12 through the heat source side discharge branch pipe 21d and the discharge side shut-off valve 31, and the rest is used as the heat source. It is sent to the heat source side heat exchanger 24 through the side switching mechanism 23 and the first heat source side gas refrigerant tube 23a. The high-pressure heat-source-side refrigerant sent to the heat-source-side heat exchanger 24 radiates heat by exchanging heat with outdoor air supplied by the heat-source-side fan 32 in the heat source-side heat exchanger 24. The high-pressure heat-source-side refrigerant that has radiated heat in the heat-source-side heat exchanger is sent to the supercooler 27 through the heat source-side expansion valve 25. The heat source side refrigerant sent to the subcooler 27 is cooled so as to be in a supercooled state by exchanging heat with the heat source side refrigerant branched from the heat source side liquid refrigerant tube 24a to the suction return tube 26. The heat source side refrigerant flowing through the suction return pipe 26 is returned to the heat source side suction pipe 21c. The heat source side refrigerant cooled in the subcooler 27 is sent from the heat source unit 2 to the liquid refrigerant communication tube 13 through the heat source side liquid refrigerant tube 24a and the liquid side shut-off valve 29.

The high-pressure heat source side refrigerant sent to the discharge refrigerant communication tube 12 is sent to the first usage unit 4a. The high-pressure heat-source-side refrigerant sent to the first usage unit 4a is sent to the first usage-side heat exchanger 41a through the first usage-side discharge refrigerant tube 46a and the first usage-side discharge check valve 49a. The high-pressure heat-source-side refrigerant sent to the first usage-side heat exchanger 41a exchanges heat with the low-pressure usage-side refrigerant in the refrigeration cycle circulating in the usage-side refrigerant circuit 40a in the first usage-side heat exchanger 41a. To dissipate heat. The high-pressure heat-source-side refrigerant radiated in the first usage-side heat exchanger 41a is sent from the first usage unit 4a to the liquid refrigerant communication tube 13 through the first usage-side flow rate adjustment valve 42a and the first usage-side liquid refrigerant tube 45a. It is done.
The heat source side refrigerant sent from the heat source unit 2 and the first usage unit 4a to the liquid refrigerant communication tube 13 merges in the liquid refrigerant communication tube 13 and is sent to the second usage unit 10a. The heat-source-side refrigerant sent to the second usage unit 10a is sent to the second usage-side flow rate adjustment valve 102a. The heat-source-side refrigerant sent to the second usage-side flow rate adjustment valve 102a is depressurized by the second usage-side flow rate adjustment valve 102a to be in a low-pressure gas-liquid two-phase state, and is passed through the second usage-side liquid refrigerant tube 103a. 2 is sent to the use side heat exchanger 101a. The low-pressure heat-source-side refrigerant sent to the second usage-side heat exchanger 101a evaporates by exchanging heat with the air medium supplied by the usage-side fan 105a in the second usage-side heat exchanger 101a. Cool the room. The low-pressure heat-source-side refrigerant evaporated in the second usage-side heat exchanger 101a is sent from the second usage unit 10a to the gas refrigerant communication tube 14 through the second usage-side gas refrigerant tube 104a.

The low-pressure heat source side refrigerant sent to the gas refrigerant communication tube 14 is sent to the heat source unit 2. The low-pressure heat source side refrigerant sent to the heat source unit 2 is sent to the heat source side accumulator 28 through the gas side shut-off valve 30, the second heat source side gas refrigerant tube 23b, and the heat source side switching mechanism 23. The low-pressure heat source side refrigerant sent to the heat source side accumulator 28 is again sucked into the heat source side compressor 21 through the heat source side suction pipe 21c.
On the other hand, in the usage-side refrigerant circuit 40a, the low-pressure usage-side refrigerant in the refrigeration cycle circulating in the usage-side refrigerant circuit 40a is heated and evaporated by the heat radiation of the heat-source-side refrigerant in the first usage-side heat exchanger 41a. The low-pressure usage-side refrigerant evaporated in the first usage-side heat exchanger 41a is sent to the usage-side accumulator 67a through the second cascade-side gas refrigerant tube 69a. The low-pressure use-side refrigerant sent to the use-side accumulator 67a is sucked into the use-side compressor 62a through the cascade-side suction pipe 71a, compressed to a high pressure in the refrigeration cycle, and then discharged to the cascade-side discharge pipe 70a. . The high-pressure use-side refrigerant discharged to the cascade-side discharge pipe 70a is sent to the refrigerant-water heat exchanger 65a through the first cascade-side gas refrigerant pipe 72a. The high-pressure use-side refrigerant sent to the refrigerant-water heat exchanger 65a radiates heat by exchanging heat with the aqueous medium circulating in the aqueous medium circuit 80a by the circulation pump 43a in the refrigerant-water heat exchanger 65a. The high-pressure use-side refrigerant that has radiated heat in the refrigerant-water heat exchanger 65a is decompressed in the refrigerant-water heat exchange side flow rate control valve 66a to become a low-pressure gas-liquid two-phase state, and passes through the cascade-side liquid refrigerant pipe 68a. Again, it is sent to the first usage side heat exchanger 41a.

In the aqueous medium circuit 80a, the aqueous medium circulating in the aqueous medium circuit 80a is heated by the heat radiation of the use-side refrigerant in the refrigerant-water heat exchanger 65a. The aqueous medium heated in the refrigerant-water heat exchanger 65a is drawn into the circulation pump 43a through the first usage-side water outlet pipe 48a, and after being pressurized, is sent from the first usage unit 4a to the aqueous medium communication pipe 16a. It is done. The aqueous medium sent to the aqueous medium communication pipe 16a is sent to the hot water storage unit 8a through the aqueous medium side switching mechanism 161a. The aqueous medium sent to the hot water storage unit 8a exchanges heat with the aqueous medium in the hot water storage tank 81a in the heat exchange coil 82a to radiate heat, thereby heating the aqueous medium in the hot water storage tank 81a.
Thus, the operation in the hot water supply / cooling operation mode in which the hot water supply operation of the first usage unit 4a is performed and the cooling operation of the second usage unit 10a is performed is performed.

Here, even in the configuration of the heat pump system 300 in which the first use unit 4a for hot water supply operation and the second use unit 10a for air conditioning operation are connected to the heat source unit 2 so that the hot water supply and cooling operation can be performed, the second Similarly to the heat pump system 200 (see FIG. 6) in the embodiment, the discharge saturation temperature control of each refrigerant circuit 20 and 40a and the supercooling degree control of each heat exchanger 41a and 65a outlet are performed.
Thereby, in this heat pump system 300, not only the effect similar to the heat pump system 200 in 2nd Embodiment can be acquired, but an aqueous medium is heated by the 1st utilization side heat exchanger 41a and the utilization side refrigerant circuit 40a. The cooling heat obtained by the heat source side refrigerant by performing the operation and heating the aqueous medium can be used for the operation of cooling the air medium by the evaporation of the heat source side refrigerant in the second usage side heat exchanger 101a. Therefore, for example, the aqueous medium heated by the first usage-side heat exchanger 41a and the usage-side refrigerant circuit 40a is used for hot water supply, and the air medium cooled in the second usage-side heat exchanger 101a is used indoors. The cooling heat obtained by the heat-source-side refrigerant by heating the aqueous medium, such as for cooling It can be, thereby, it is possible to achieve energy saving.

(1) Modification 1
As in the heat pump system 300 described above (see FIG. 12), the first usage unit 4a for hot water supply operation and the second usage unit 10a for air conditioning operation are connected to the heat source unit 2 so as to enable hot water supply and cooling operation. Also in the configuration, as in the heat pump system 200 (see FIG. 6) in the first modification of the second embodiment, the oil separation mechanism is not provided for the discharge of the use side compressor 62a. However, it is easy to be introduced into the refrigerant-water heat exchanger 65a functioning as a heat radiator for the use-side refrigerant, and in a high-temperature condition, the liquid-use use-side refrigerant and the refrigeration oil are contained in the refrigerant-water heat exchanger 65a. Therefore, the refrigerating machine oil tends to accumulate in the refrigerant-water heat exchanger 65a that functions as a heat radiator for the use-side refrigerant. In addition, when the degree of supercooling at the outlet of the refrigerant-water heat exchanger 65a is being controlled, the amount of liquid-side usage-side refrigerant corresponding to the usage-side refrigerant subcooling degree SC2 is within the refrigerant-water heat exchanger 65a. Therefore, the two-phase separation between the use-side refrigerant in the liquid state and the refrigerating machine oil is more likely to occur.

Therefore, in this heat pump system 300, the same oil recovery operation control (see FIG. 2) as that in the heat pump system 200 (see FIG. 6) in the second embodiment is performed.
Thereby, it is possible to prevent a shortage of refrigerating machine oil in the use side compressor 62a. In addition, during this oil recovery operation, the operation of heating the water refrigerant can be continued by causing the refrigerant-water heat exchanger 65a to function as a radiator of the use-side refrigerant, thereby performing the oil recovery operation. The adverse effect on hot water supply operation, hot water supply heating operation and hot water supply cooling operation can be minimized.
(2) Modification 2
In the above-described heat pump system 300 (see FIG. 12), as shown in FIG. 13, the refrigerant-water heat exchanger 65a functions as a radiator for the usage-side refrigerant and the first usage-side heat exchanger 41a serves as the usage-side refrigerant. Use side heat radiation operation state for functioning as an evaporator of the user and the use side causing the refrigerant-water heat exchanger 65a to function as an evaporator for the use side refrigerant and the first use side heat exchanger 41a to function as a radiator for the use side refrigerant A first usage side switching mechanism 64a (similar to the first usage side switching mechanism 64a provided in the heat pump system 200 in the second embodiment) capable of switching between the evaporation operation states is further provided in the usage side refrigerant circuit 40a; The first usage unit 4 a is further connected to the gas refrigerant communication tube 14, and the first usage-side heat exchanger 41 a is introduced from the discharge refrigerant communication tube 12. Switching between an aqueous medium heating operation state that functions as a refrigerant radiator and an aqueous medium cooling operation state that causes the first usage side heat exchanger 41a to function as an evaporator of a heat source side refrigerant introduced from the liquid refrigerant communication tube 13 is possible. A possible second usage side switching mechanism 53a may be further provided.

Here, the first use side gas refrigerant pipe 54a is connected to the gas side of the flow path through which the heat source side refrigerant of the first use side heat exchanger 41a flows together with the first use side discharge refrigerant pipe 46a. The first refrigerant gas refrigerant pipe 54a is connected to the gas refrigerant communication pipe 14. The second usage-side switching mechanism 53a includes a first usage-side discharge opening / closing valve 55a (here, the first usage-side discharge check valve 49a is omitted) provided in the first usage-side discharge refrigerant pipe 46a, A first use side gas on / off valve 56a provided in the side gas refrigerant pipe 54a, by opening the first use side discharge on / off valve 55a and closing the first use side gas on / off valve 56a. The aqueous medium heating operation state is set, the first usage side discharge on / off valve 55a is closed, and the first usage side gas on / off valve 56a is opened to enter the aqueous medium cooling operation state. Each of the first usage-side discharge on-off valve 55a and the first usage-side gas on-off valve 56a is an electromagnetic valve that can be controlled to open and close. The second usage side switching mechanism 53a may be constituted by a three-way valve or the like.

In the heat pump system 300 having such a configuration, when it is determined that defrosting of the heat source side heat exchanger 24 is necessary by operations in the hot water supply operation mode, the heating operation mode, and the hot water supply heating operation mode, the heat source side By setting the switching mechanism 23 to the heat source side heat radiation operation state, the heat source side heat exchanger 24 functions as a heat source side refrigerant radiator, and the second usage side heat exchanger 101a functions as a heat source side refrigerant evaporator. In addition, by setting the first usage side switching mechanism 64a to the usage side evaporation operation state, the refrigerant-water heat exchanger 65a functions as an evaporator of the usage side refrigerant, and the first usage side heat exchanger 41a is used on the usage side. A defrosting operation that functions as a refrigerant radiator can be performed.
Hereinafter, the operation in the defrosting operation will be described with reference to FIG.
First, it is determined whether or not a predetermined defrosting operation start condition is satisfied (that is, whether or not the heat source side heat exchanger 24 needs to be defrosted) (step S11). Here, whether or not the defrosting operation start condition is satisfied depends on whether or not the defrosting time interval Δtdf (that is, the accumulated operation time from the end of the previous defrosting operation) has reached a predetermined defrosting time interval set value Δtdfs. judge.

And when it determines with satisfy | filling the defrost operation start conditions, the following defrost operations are started (step S12).
When the defrosting operation is started, in the heat source side refrigerant circuit 20, the heat source side switching mechanism 23 is switched to the heat source side heat radiation operation state (the state indicated by the solid line of the heat source side switching mechanism 23 in FIG. 13). In the usage-side refrigerant circuit 40a, the first usage-side switching mechanism 64a is switched to the usage-side evaporation operation state (the state indicated by the broken line of the first usage-side switching mechanism 64a in FIG. 13). 53a is switched to the aqueous medium cooling operation state (that is, the first usage-side discharge on-off valve 55a is closed and the first usage-side gas on-off valve 56a is opened), and the suction return expansion valve 26a is closed. It becomes a state.
In the heat source side refrigerant circuit 20 in such a state, the low pressure heat source side refrigerant in the refrigeration cycle is sucked into the heat source side compressor 21 through the heat source side suction pipe 21c and compressed to a high pressure in the refrigeration cycle, and then the heat source side refrigerant circuit 20 is cooled. It is discharged to the discharge pipe 21b. The high pressure heat source side refrigerant discharged to the heat source side discharge pipe 21b is separated from the refrigerating machine oil in the oil separator 22a. The refrigerating machine oil separated from the heat source side refrigerant in the oil separator 22a is returned to the heat source side suction pipe 21c through the oil return pipe 22b. The high-pressure heat-source-side refrigerant from which the refrigerating machine oil has been separated is sent to the heat-source-side heat exchanger 24 through the heat-source-side switching mechanism 23 and the first heat-source-side gas refrigerant tube 23a. The high-pressure heat-source-side refrigerant sent to the heat-source-side heat exchanger 24 radiates heat by exchanging heat with ice attached to the heat-source-side heat exchanger 24 in the heat-source-side heat exchanger 24. The high-pressure heat-source-side refrigerant that has radiated heat in the heat-source-side heat exchanger is sent to the supercooler 27 through the heat source-side expansion valve 25. Since the heat source side refrigerant sent to the subcooler 27 does not flow through the suction return pipe 26, the heat source unit refrigerant passes through the heat source side liquid refrigerant tube 24a and the liquid side shut-off valve 29 without performing heat exchange. 2 to the liquid refrigerant communication tube 13.

The heat-source-side refrigerant sent to the liquid refrigerant communication tube 13 branches in the liquid refrigerant communication tube 13 and is sent to the first usage unit 4a and the second usage unit 10a.
The heat-source-side refrigerant sent to the second usage unit 10a is sent to the second usage-side flow rate adjustment valve 102a. The heat-source-side refrigerant sent to the second usage-side flow rate adjustment valve 102a is depressurized by the second usage-side flow rate adjustment valve 102a to become a low-pressure gas-liquid two-phase state, and through the second usage-side liquid refrigerant tube 103a, It is sent to the second usage side heat exchanger 101a. The low-pressure heat-source-side refrigerant sent to the second usage-side heat exchanger 101a evaporates by exchanging heat with the air medium supplied by the usage-side fan 105a in the second usage-side heat exchanger 101a. The low-pressure heat-source-side refrigerant evaporated in the second usage-side heat exchanger 101a is sent from the second usage unit 10a to the gas refrigerant communication tube 14 through the second usage-side gas refrigerant tube 104a.

The heat-source-side refrigerant sent to the first usage unit 4a is sent to the first usage-side flow rate adjustment valve 42a. The heat-source-side refrigerant sent to the first usage-side flow rate adjustment valve 42a is depressurized in the first usage-side flow rate adjustment valve 42a to become a low-pressure gas-liquid two-phase state, and through the first usage-side liquid refrigerant tube 45a, It is sent to the first usage side heat exchanger 41a. The low-pressure heat-source-side refrigerant sent to the first usage-side heat exchanger 41a exchanges heat with the high-pressure usage-side refrigerant in the refrigeration cycle circulating in the usage-side refrigerant circuit 40a in the first usage-side heat exchanger 41a. Evaporate. The low-pressure heat source side refrigerant evaporated in the first usage-side heat exchanger 41a is the low-pressure heat source-side refrigerant evaporated in the first usage-side heat exchanger 41a, and the first usage side constituting the second usage-side switching mechanism 53a. The gas is sent from the first usage unit 4a to the gas refrigerant communication pipe 14 through the gas on-off valve 56a and the first usage-side gas refrigerant pipe 54a.

The heat-source-side refrigerant sent from the second usage unit 10a and the first usage unit 4a to the gas refrigerant communication tube 14 merges in the gas refrigerant communication tube 14 and is sent to the heat source unit 2. The low-pressure heat source side refrigerant sent to the heat source unit 2 is sent to the heat source side accumulator 28 through the gas side shut-off valve 30, the second heat source side gas refrigerant tube 23b, and the heat source side switching mechanism 23. The low-pressure heat source side refrigerant sent to the heat source side accumulator 28 is again sucked into the heat source side compressor 21 through the heat source side suction pipe 21c.
On the other hand, in the usage-side refrigerant circuit 40a, the high-pressure usage-side refrigerant in the refrigeration cycle that circulates in the usage-side refrigerant circuit 40a is radiated by evaporation of the heat-source-side refrigerant in the first usage-side heat exchanger 41a. The high-pressure usage-side refrigerant that has radiated heat in the first usage-side heat exchanger 41a is sent to the refrigerant-water heat exchange side flow rate adjustment valve 66a. The high-pressure use-side refrigerant sent to the refrigerant-water heat exchange side flow rate adjustment valve 66a is depressurized by the refrigerant-water heat exchange side flow rate adjustment valve 66a to become a low-pressure gas-liquid two-phase state, and the cascade-side liquid refrigerant. It is sent to the refrigerant-water heat exchanger 65a through the pipe 68a. The low-pressure use-side refrigerant sent to the refrigerant-water heat exchanger 65a evaporates in the refrigerant-water heat exchanger 65a by exchanging heat with the aqueous medium circulating in the aqueous medium circuit 80a by the circulation pump 43a. The low-pressure usage-side refrigerant evaporated in the refrigerant-water heat exchanger 65a is sent to the usage-side accumulator 67a through the first cascade-side gas refrigerant tube 72a and the first usage-side switching mechanism 64a. The low-pressure use-side refrigerant sent to the use-side accumulator 67a is sucked into the use-side compressor 62a through the cascade-side suction pipe 71a, compressed to a high pressure in the refrigeration cycle, and then discharged to the cascade-side discharge pipe 70a. . The high-pressure use-side refrigerant discharged to the cascade-side discharge pipe 70a is sent again to the first use-side heat exchanger 41a through the first use-side switching mechanism 64a and the second cascade-side gas refrigerant pipe 69a.

In this way, the heat source side heat exchanger 24 is made to function as a heat source side refrigerant radiator by setting the heat source side switching mechanism 23 to the heat source side heat radiation operation state, and the second usage side heat exchanger 101a is set to the heat source side. The refrigerant-water heat exchanger 65a functions as a usage-side refrigerant evaporator by causing the first usage-side switching mechanism 64a to be in the usage-side evaporation operation state, while functioning as a refrigerant evaporator, and the first usage side A defrosting operation for causing the heat exchanger 41a to function as a heat radiator for the use side refrigerant (that is, as an evaporator for the heat source side refrigerant) is started.
Then, it is determined whether or not a predetermined defrosting operation end condition is satisfied (that is, whether or not the defrosting of the heat source side heat exchanger 24 is completed) (step S13). Here, whether or not the heat source side heat exchanger temperature Thx has reached a predetermined defrosting completion temperature Thxs or a defrosting operation time tdf that is an elapsed time from the start of the defrosting operation is a predetermined defrosting operation setting time tdfs. It is determined whether or not the defrosting operation end condition is satisfied depending on whether or not it has been reached.

And when it determines with satisfy | filling the defrost operation completion | finish conditions, the process which complete | finishes a defrost operation and returns to hot water supply operation mode is performed (step S14).
Thereby, in this heat pump system 300, when the heat source side heat exchanger 24 is defrosted, the heat source side heat exchanger 24 is placed in the heat source side heat dissipation operation state by setting the heat source side switching mechanism 23 to the heat source side refrigerant radiator. The refrigerant-water heat exchanger 65a functions as an evaporator of the use side refrigerant by setting the first use side switching mechanism 64a to the use side evaporation operation state, and the first use side heat exchange is performed. Since the heat exchanger 41a is caused to function as a radiator for the usage-side refrigerant, the heat-source-side refrigerant radiated and cooled in the heat-source-side heat exchanger 24 is radiated from the usage-side refrigerant in the first usage-side heat exchanger 41a. It is possible to heat the use-side refrigerant that has been heated by the first heat-side heat exchanger 41a and is radiated and cooled in the first use-side heat exchanger 41a by evaporating in the refrigerant-water heat exchanger 65a. Thus, it is possible to reliably perform defrosting of the heat source-side heat exchanger 24. In addition, since the second usage-side heat exchanger 101a also functions as a heat source-side refrigerant evaporator, the defrosting operation time tdf can be shortened, and the air cooled in the second usage unit 10a. It can suppress that the temperature of a medium becomes low.

Further, in the heat pump system 300 having such a configuration, when the oil recovery operation is necessary in the hot water supply operation mode, the hot water supply heating operation mode, or the hot water supply cooling operation mode, the first use side switching mechanism 64a is used on the use side heat dissipation. The oil recovery operation of the second modification of the second embodiment can be performed while maintaining the operation state (that is, without switching).
(3) Modification 3
As in the heat pump system 300 (see FIG. 13) according to the second modification, the first heating side heat exchanger 41a functions as a radiator for the heat source side refrigerant introduced from the discharge refrigerant communication tube 12, and the first heating operation state and In the configuration provided with the second usage side switching mechanism 53a capable of switching between the water medium cooling operation state in which the first usage side heat exchanger 41a functions as an evaporator of the heat source side refrigerant introduced from the liquid refrigerant communication tube 13. When the operation of the first usage unit 4a is stopped and the operation of the second usage unit 10a (cooling operation or heating operation) is performed (that is, when the discharge refrigerant communication pipe 12 is not used), the heat source side compressor The heat source side refrigerant discharged from 21 accumulates in the discharge refrigerant communication pipe 12, and the flow rate of the heat source side refrigerant drawn into the heat source side compressor 21 is insufficient (that is, the refrigerant circulation amount is insufficient). Have it.

Therefore, in this heat pump system 300, as shown in FIG. 14, the discharge refrigerant communication tube 12 and the gas refrigerant communication tube are used when the refrigerant second use side switching mechanism 53a is in either the aqueous medium heating operation state or the aqueous medium cooling operation state. 14 is provided with a first refrigerant recovery mechanism 57a that communicates with the first refrigerant. Here, the 1st refrigerant | coolant collection | recovery mechanism 57a is a refrigerant | coolant pipe | tube which has a capillary tube, and the one end connects the 1st utilization side discharge on-off valve 55a and the discharge refrigerant | coolant communication pipe | tube 12 among the 1st utilization side discharge refrigerant pipes 46a. The other end is connected to the connecting portion, and the other end is connected to the portion of the first usage-side gas refrigerant tube 54a that connects the first usage-side gas on / off valve 56a and the gas refrigerant communication tube 14, The discharge refrigerant communication pipe 12 and the gas refrigerant communication pipe 14 are communicated regardless of the open / close state of the use side discharge on / off valve 55a and the first use side gas on / off valve 56a.

Thereby, in this heat pump system 300, since the heat-source-side refrigerant does not easily accumulate in the discharge refrigerant communication tube 12, it is possible to suppress the occurrence of insufficient refrigerant circulation in the heat-source-side refrigerant circuit 20.
Further, as in the heat pump system 300 (see FIG. 13) according to the second modification, the aqueous medium heating operation state in which the first usage-side heat exchanger 41a functions as a radiator for the heat-source-side refrigerant introduced from the discharge refrigerant communication tube 12. And a second usage-side switching mechanism 53a capable of switching between an aqueous medium cooling operation state in which the first usage-side heat exchanger 41a functions as an evaporator of the heat source-side refrigerant introduced from the liquid refrigerant communication tube 13. In the configuration, when the operation of the first usage unit 4a is stopped and the operation of the second usage unit 10a (cooling operation or heating operation) is performed, the heat source side refrigerant accumulates in the first usage side heat exchanger 41a, There is a possibility that the flow rate of the heat source side refrigerant sucked into the heat source side compressor 21 is insufficient (that is, the refrigerant circulation amount is insufficient).

Therefore, in the heat pump system 300, as shown in FIG. 14, the first usage side heat exchanger 41a and the gas refrigerant are used in the second usage side switching mechanism 53a in both the aqueous medium heating operation state and the aqueous medium cooling operation state. A second refrigerant recovery mechanism 58a that communicates with the communication pipe 14 is provided. Here, the 2nd refrigerant | coolant collection | recovery mechanism 58a is a refrigerant | coolant pipe | tube which has a capillary tube, The one end is the gas side and 1st utilization side of the 1st utilization side heat exchanger 41a among the 1st utilization side gas refrigerant pipes 54a. The other end is connected to a portion connecting the first use side gas on / off valve 56a and the gas refrigerant communication tube 14 in the first use side gas refrigerant tube 54a. Even when the operation of the first usage unit 4a is stopped, the gas side and the gas refrigerant communication pipe of the first usage side heat exchanger 41a are bypassed by bypassing the first usage side gas on-off valve 56a. 14 is communicated.

Thereby, in this heat pump system 300, since it becomes difficult for the heat source side refrigerant to accumulate in the 1st utilization side heat exchanger 41a, generation | occurrence | production of insufficient refrigerant | coolant circulation amount in the heat source side refrigerant circuit 20 can be suppressed.
Further, in the heat pump system 300 (see FIG. 13) in the modified example, the second usage side switching mechanism 53a is configured by the first usage side discharge on / off valve 55a and the first usage side gas on / off valve 56a. In any of the accompanying operation modes, the heat source side refrigerant is supplied from only the discharged refrigerant communication tube 12 to the first usage unit 4a.
However, in the hot water supply operation mode and the hot water supply / air heating operation mode among the operation modes involving the hot water supply operation, the heat source side refrigerant is at a high pressure in the refrigeration cycle not only in the discharge refrigerant communication tube 12 but also in the gas refrigerant communication tube 14. For this reason, in the hot water supply operation mode and the hot water supply / air heating operation mode, not only the discharge refrigerant communication tube 12 but also the gas refrigerant communication tube 14 may be able to send the high-pressure heat source side refrigerant to the first usage unit 4a. .

Therefore, in this heat pump system 300, as shown in FIG. 14, the first usage-side gas check valve 59a and the first usage-side bypass refrigerant tube 60a are further provided in the first usage-side gas refrigerant tube 54a, A second usage side switching mechanism 53a is configured together with the usage side discharge on / off valve 55a and the first usage side gas on / off valve 56a. Here, the 1st utilization side gas check valve 59a is provided in the part which connects the 1st utilization side gas on-off valve 56a and the gas refrigerant communication pipe | tube 14 among the 1st utilization side gas refrigerant pipes 54a. The first usage-side gas check valve 59a allows the flow of the heat-source-side refrigerant from the first usage-side heat exchanger 41a toward the gas refrigerant communication tube 14, and from the gas refrigerant communication tube 14 to the first usage-side heat exchanger 41a. This is a check valve that prohibits the flow of the heat source side refrigerant toward the heat source side, whereby the flow of the heat source side refrigerant toward the first use side heat exchanger 41a from the gas refrigerant communication tube 14 through the first use side gas on-off valve 56a. Is now prohibited. The first usage-side bypass refrigerant pipe 60a is connected to the first usage-side gas refrigerant pipe 54a so as to bypass the first usage-side gas on-off valve 56a and the first usage-side gas check valve 59a. A part of the side gas refrigerant pipe 54a is constituted. The first usage-side bypass refrigerant pipe 60a allows the flow of the heat source-side refrigerant from the gas refrigerant communication pipe 14 toward the first usage-side heat exchanger 41a, and the first usage-side heat exchanger 41a passes the gas refrigerant communication pipe 14. A first usage-side bypass check valve 59a that prohibits the flow of the heat-source-side refrigerant toward the first usage-side heat exchange from the gas refrigerant communication tube 14 through the first usage-side bypass refrigerant tube 60a is provided. The flow of the heat source side refrigerant toward the container 41a is allowed.

Thereby, in this heat pump system 300, in the hot water supply operation mode and the hot water supply heating operation mode, not only the discharge refrigerant communication tube 12 but also the gas refrigerant communication tube 14 can send the high-pressure heat source side refrigerant to the first usage unit 4a. As a result, the pressure loss of the heat-source-side refrigerant supplied from the heat source unit 2 to the first usage unit 4a is reduced, which can contribute to improvements in hot water supply capacity and operating efficiency.
(4) Modification 4
In the above-described heat pump system 300 (see FIGS. 12 to 14), one first usage unit 4a and one second usage unit 10a are connected to the heat source unit 2 via refrigerant communication tubes 12, 13, and 14. However, as shown in FIGS. 15 to 17 (here, the hot water heating unit, the hot water storage unit, the aqueous medium circuits 80a and 80b, etc. are omitted), a plurality of (here, two) first usage units. 4a and 4b are connected to each other in parallel via the refrigerant communication pipes 13 and 14, and / or a plurality (here, two) of the second usage units 10a and 10b are connected to the refrigerant. The pipes 12, 13, and 14 may be connected to each other in parallel. Since the configuration of the first usage unit 4b is the same as that of the first usage unit 4a, the configuration of the first usage unit 4b is indicated by a suffix “a” indicating each part of the first usage unit 4a. Subscript “b” is attached instead of “,” and description of each part is omitted. In addition, since the configuration of the second usage unit 10b is the same as the configuration of the second usage unit 10a, the configuration of the second usage unit 10b is indicated by a subscript “a” indicating each part of the second usage unit 10a. Subscript “b” is attached instead of “,” and description of each part is omitted.

Thereby, in these heat pump systems 300, it can respond to a plurality of places and uses which require heating of an aqueous medium, and can respond to a plurality of places and uses which require cooling of an air medium.
(5) Modification 5
In the above-described heat pump system 300 (see FIGS. 12 to 17), the second usage-side flow rate adjusting valves 102a and 102b are provided in the second usage units 10a and 10b, but as shown in FIG. Then, the hot water heating unit, the hot water storage unit, the aqueous medium circuit 80a, etc. are not shown), the second usage side flow rate adjustment valves 102a, 102b are omitted from the second usage units 10a, 10b, and the second usage side flow rate adjustment valve is omitted. An expansion valve unit 17 having 102a and 102b may be provided.

(Other embodiments)
As mentioned above, although embodiment of this invention and its modification were demonstrated based on drawing, specific structure is not restricted to these embodiment and its modification, It changes in the range which does not deviate from the summary of invention. Is possible.
<A>
In the heat pump systems 200 and 300 according to the second and third embodiments and the modifications thereof, the second usage units 10a and 10b are not usage units used for indoor air conditioning, and are different from air conditioning such as refrigeration and freezing. It may be used for a purpose.
<B>
In the heat pump system 300 according to the third embodiment and the modification thereof, for example, the gas refrigerant communication pipe 14 is connected to the low-pressure heat source side in the refrigeration cycle by communicating the second heat source side gas refrigerant pipe 23b and the heat source side suction pipe 21c. The refrigerant is used as a refrigerant pipe through which the refrigerant flows, whereby the second usage- side heat exchangers 101a and 101b function only as an evaporator for the heat-source-side refrigerant, and the second usage units 10a and 10b are usage units dedicated to cooling. It may be. Also in this case, operation in the hot water supply / cooling operation mode is possible, and energy saving can be achieved.

<C>
In the heat pump systems 1, 200, and 300 according to the first to third embodiments and the modifications thereof, the HFC-134a is used as the use-side refrigerant. However, the present invention is not limited to this. 2, 3, 3, 3-tetrafluoro-1-propene) or the like, the pressure corresponding to the saturated gas temperature of 65 ° C. is not more than 2.8 MPa, preferably not more than 2.0 MPa in terms of gauge pressure. .

If the present invention is used, a high-temperature aqueous medium can be obtained in a heat pump system capable of heating an aqueous medium using a heat pump cycle.

DESCRIPTION OF SYMBOLS 1,200,300 Heat pump system 2 Heat source unit 4a, 4b 1st utilization unit 20 Heat source side refrigerant circuit 21 Heat source side compressor 24 Heat source side heat exchanger 40a, 40b Utilization side refrigerant circuit 41a, 41b 1st utilization side heat exchanger 62a, 62b Use side compressors 65a, 65b Refrigerant- water heat exchangers 66a, 66b Refrigerant-water heat exchange side flow control valves 67a, 67b Use side accumulators

JP 60-164157 A

Claims (4)

1. Functions as a heat source side compressor (21) that compresses the heat source side refrigerant, a first use side heat exchanger (41a, 41b) that can function as a radiator of the heat source side refrigerant, and an evaporator of the heat source side refrigerant A heat source side refrigerant circuit (20) having a heat source side heat exchanger (24) capable of
   A use side compressor (62a, 62b) that compresses a use side refrigerant whose pressure corresponding to a saturated gas temperature of 65 ° C. is 2.8 MPa or less as a gauge pressure, and functions as a radiator for the use side refrigerant to heat the aqueous medium Refrigerant-water heat exchangers (65a, 65b) that can be used, and the first user-side heat exchangers (41a, 41b) that can function as evaporators of the user-side refrigerant by radiating heat from the heat-source-side refrigerant A use side refrigerant circuit (40a, 40b) having
   The usage-side compressor, the first usage-side heat exchanger, and the refrigerant-water heat exchanger constitute a first usage unit (4a, 4b),
   The length of the refrigerant pipe from the first use side heat exchanger functioning as an evaporator of the use side refrigerant to the use side compressor is 3 m or less,
   The use side refrigerant circuit is not provided with an oil separation mechanism for separating the refrigeration oil contained in the use side refrigerant discharged from the use side compressor and returning it to the suction of the use side compressor. ,
   The weight of the utilization side refrigerant enclosed in the utilization side refrigerant circuit is 1 to 3 times the weight of the refrigerating machine oil enclosed for lubrication of the utilization side compressor.
   Heat pump system (1, 200, 300).
2. The heat pump system (1, 200, 300) according to claim 1, wherein the use-side refrigerant has a gauge pressure of 2.0 MPa or less corresponding to a saturated gas temperature of 65 ° C.
3. The use side refrigerant circuit (40a, 40b) includes a use side accumulator (67a, 67b) capable of temporarily storing a use side refrigerant for suction of the use side compressor (62a, 62b), and the refrigerant- A refrigerant-water heat exchange side flow rate adjustment valve (66a, 66b) capable of changing the flow rate of the use side refrigerant flowing through the water heat exchanger (65a, 65b);
   When it is determined that the use-side compressor is short of refrigerating machine oil, the use-side refrigerant including the refrigerating machine oil in the refrigerant-water heat exchanger is changed to the refrigerant-hydrothermal exchange side flow control valve and the refrigerant An oil recovery operation is performed to return to the usage-side accumulator through the first usage-side heat exchanger.
   The heat pump system (1, 200, 300) according to claim 1 or 2.
4. Whether or not the use side compressor (62a, 62b) is deficient in refrigerating machine oil is determined based on the temperature of the use side refrigerant at the discharge of the use side compressor or the refrigerant-water heat exchanger (65a, 65b). The heat pump system (1, 200, 300) according to claim 3, which is performed based on the temperature of the aqueous medium at the outlet.

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